Search Results (458)

Human induced pluripotent stem cells (hiPSCs) are widely used in basic research because of their versatility and ability to differentiate into multiple cell types. In particular, differentiating hiPSCs into cardiac cells (hiPSC-CMs) has been an important milestone in cardiac pathophysiology studies. Although hiPSC-CMs offer a model for human cardiomyocytes, they still exhibit characteristics linked to the fetal cardiac cell phenotype. One important feature that prevents hiPSC-CMs from being identified as adult cells relates to their metabolism, which is a key factor in defining a mature phenotype capable of sustaining the workload requirements characteristic of fully differentiated cardiomyocytes. This review aims to present the most relevant strategies in terms of culture medium composition, culture times, and 3D culture methods that have been developed to promote the metabolic maturation of hiPSC-CMs, which are now widely used. Defining a standardized and universally accepted protocol would enable the creation of a cellular model for studies of cardiac pathophysiology from a patient-specific perspective and for drug screening. Full article

New approach methodologies (NAMs), including microphysiological systems (MPSs), can recapitulate structural and functional complexities of organs. Vanoxerine was reported to induce cardiac adverse events, including torsade de points (TdP), in a Phase III clinical trial. Despite earlier nonclinical animal models and Phase I–II clinical trials, events of QT prolongation or proarrhythmia were not observed. Here, we utilized cardiac NAMs to evaluate the functional consequences of vanoxerine treatment on human cardiac excitation–contraction coupling. The cardiac MPS used in this study was a microfabricated fluidic culture platform with human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) capable of evaluating voltage, intracellular calcium handling, and contractility. Likewise, the hiPSC-CM comprehensive in vitro proarrhythmia assay (CiPA) was employed based on multielectrode array (MEA). Vanoxerine treatment delayed repolarization in a concentration-dependent manner and induced proarrhythmic events in both NAM platforms. The complex cardiac MPS displayed a frequency-dependent vanoxerine response such that EADs were eliminated at a faster pacing rate (1.5 Hz). Moreover, exposure analysis revealed a 99% vanoxerine loss in the cardiac MPS. TdP risk analysis demonstrated high to intermediate TdP risk at clinically relevant concentrations of vanoxerine and frequency-independent EAD events in the hiPSC-CM CiPA model. These findings demonstrate that nonclinical cardiac NAMs can recapitulate clinical outcomes, including detection of vanoxerine-induced delayed repolarization and proarrhythmic effects. Moreover, this work provides a foundation to evaluate the safety and efficacy of novel compounds to reduce the dependence on animal studies. Full article

Skeletal muscle regeneration requires a reliable source of myogenic progenitor cells capable of forming new fibers and creating a self-renewing satellite cell pool. Human induced pluripotent stem cell (hiPSC)-derived teratomas have emerged as a novel in vivo platform for generating skeletal myogenic progenitors, although in vivo studies to date have provided only an early single-time-point snapshot. In this study, we isolated a specific population of CD82⁺ ERBB3⁺ NGFR⁺ cells from human iPSC-derived teratomas and verified their long-term in vivo regenerative capacity following transplantation into NSG-mdx^4Cv mice. Transplanted cells engrafted, expanded, and generated human Dystrophin⁺ muscle fibers that increased in size over time and persisted stably long-term. A dynamic population of PAX7⁺ human satellite cells was established, initially expanding post-transplantation and declining moderately between 4 and 8 months as fibers matured. MyHC isoform analysis revealed a time-based shift from embryonic to neonatal and slow fiber types, indicating a slow progressive maturation of the graft. We further show that these progenitors can be cryopreserved and maintain their engraftment potential. Together, these findings give insight into the evolution of teratoma-derived human myogenic stem cell grafts, and highlight the long-term regenerative potential of teratoma-derived human skeletal myogenic progenitors. Full article

Background/Objectives: Doxorubicin (DOX), a widely used anthracycline chemotherapeutic agent, is recognized for its efficacy in treating various malignancies. However, its clinical application is critically limited due to dose-dependent cardiotoxicity, predominantly induced by oxidative stress and compromised antioxidant defenses. Photobiomodulation (PBM), a non-invasive intervention that utilizes low-intensity light, has emerged as a promising therapeutic modality in regenerative medicine, demonstrating benefits such as enhanced tissue repair, reduced inflammation, and protection against oxidative damage. This investigation sought to evaluate the cardioprotective effects of PBM preconditioning in human-induced pluripotent stem cell-derived ventricular cardiomyocytes (hiPSC-vCMs) subjected to DOX-induced toxicity. Methods: Human iPSC-vCMs were allocated into three experimental groups: control cells (untreated), DOX-treated cells (exposed to 2 μM DOX for 24 h), and PBM+DOX-treated cells (preconditioned with PBM, utilizing 660 nm ±10 nm LED light at an intensity of 10 mW/cm² for 500 s, delivering an energy dose of 5 J/cm², followed by DOX exposure). Cell viability assessments were conducted in conjunction with evaluations of oxidative stress markers, including antioxidant enzyme activities and malondialdehyde (MDA) levels. Furthermore, transcriptional profiling of 40 genes implicated in cardiac dysfunction was performed using TaqMan quantitative polymerase chain reaction (qPCR), complemented by analyses of protein expression for markers of cardiac stress, inflammation, and apoptosis. Results: Exposure to DOX markedly reduced the viability of hiPSC-vCMs. The cells exhibited significant alterations in the expression of 32 out of 40 genes (80%) after DOX exposure, reflecting the upregulation of markers associated with apoptosis, inflammation, and adverse cardiac remodeling. PBM preconditioning partially restored the cell viability, modulating the expression of 20 genes (50%), effectively counteracting a substantial proportion of the dysregulation induced by DOX. Notably, PBM enhanced the expression of genes responsible for antioxidant defense, augmented antioxidant enzyme activity, and reduced oxidative stress indicators such as MDA levels. Additional benefits included downregulating stress-related mRNA markers (HSP1A1 and TNC) and apoptotic markers (BAX and TP53). PBM also demonstrated gene reprogramming effects in ventricular cells, encompassing regulatory changes in NPPA, NPPB, and MYH6. PBM reduced the protein expression levels of IL-6, TNF, and apoptotic markers in alignment with their corresponding mRNA expression profiles. Notably, PBM preconditioning showed a diminished expression of BNP, emphasizing its positive impact on mitigating cardiac stress. Conclusions: This study demonstrates that PBM preconditioning is an effective strategy for reducing DOX-induced chemotherapy-related cardiotoxicity by enhancing cell viability and modulating signaling pathways associated with oxidative stress, as well as inflammatory and hypertrophic markers. Full article

The recently identified proton-activated chloride (PAC) channel is ubiquitously expressed, and it regulates several proton-sensitive physiological and pathophysiological processes. While the PAC channel is activated by strong acids due to the binding of protons to extracellular binding sites, here, we describe the way in which weak acids inhibit the PAC channel by a mechanism involving a distinct extracellular binding site. Whole-cell patch clamp was performed on wildtype HEK293T cells, PAC-knockout HEK293 cells expressing human (h)PAC mutant constructs, and on hiPSC-derived cardiomyocytes. Proton-induced cytotoxicity was examined in HEK293T cells. Acetic acid inhibited endogenous PAC channels in HEK 293T cells in a reversible, concentration-dependent, and pH-dependent manner. The inhibition of PAC channels was also induced by lactic acid, propionic acid, itaconic acid, and β-hydroxybutyrate. Weak acids also inhibited recombinant wildtype hPAC channels and PAC-like currents in hiPSC-derived cardiomyocytes. Replacement of the extracellular arginine 93 by an alanine (hPAC–Arg93Ala) strongly reduced the inhibition by some weak acids, including arachidonic acid. Although lactic acid inhibited PAC, it did not reduce the proton-induced cytotoxicity examined in wildtype HEK 293 cells. To conclude, weak acids inhibit PAC via an extracellular mechanism involving Arg93. These data warrant further investigations into the regulation of the PAC channel by endogenous weak acids. Full article

Cardiotoxicity related to anthracyclines and trastuzumab represents a significant clinical challenge in cancer therapy, often limiting treatment efficacy and patient survival. The underlying mechanisms of cardiotoxicity involve the activation of NLRP3 and the MyD88-dependent signaling pathway. Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i), such as inclisiran, are known for their lipid-lowering effects, but emerging data indicate that they may also exert pleiotropic benefits beyond cholesterol reduction. This study investigates whether inclisiran can mitigate the cardiotoxic effects of anthracyclines and trastuzumab through reduction of NLRP3 activation and MyD88 signaling, independently of its effects on dyslipidemia. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were exposed to subclinical concentrations of doxorubicin (1 µM) and trastuzumab in sequential therapy (200 nM), alone or in combination with inclisiran (100 nM) for 24 h. After the incubation period, we performed the following tests: determination of cardiomyocytes apoptosis, analysis of intracellular reactive oxygen species, lipid peroxidation products (including malondialdehyde and 4-hydroxynonenal), intracellular mitofusin-2 and Ca⁺⁺ levels. Troponin and BNP were quantified through selective ELISA methods. A confocal laser scanning microscope was used to study cardiomyocyte morphology and F-actin staining after treatments. Moreover, pro-inflammatory studies were also performed, including the intracellular expression of NLRP-3, MyD-88 and twelve cytokines/growth factors involved in cardiotoxicity (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, IL17-α, IFN-γ, TNF-α, G-CSF, GM-CSF). Inclisiran co-incubated with doxorubicin and trastuzumab exerts significant cardioprotective effects, enhancing cell viability by 88.9% compared to only DOXO/TRA treated cells (p < 0.001 for all). Significant reduction of oxidative stress, and intracellular levels of NLRP-3, MyD88, IL-1α, IL-1β, IL-6, IL-12, IL17-α, TNF-α, G-CSF were seen in the inclisiran group vs. only DOXO/TRA (p < 0.001). For the first time, PCSK9i inclisiran has been shown to exert significant anti-inflammatory effects to reduce anthracycline-HER-2 blocking agent-mediated cardiotoxicity through NLRP-3 and Myd-88 related pathways. The overall conclusions of the study warrant further investigation of the use of PCSK9i in primary prevention of CTRCD in cancer patients, independently from dyslipidemia. Full article

Human induced pluripotent stem cells (iPSCs) offer immense potential as a source for cell therapy in spinal cord injury (SCI) and other diseases. The development of hypoimmunogenic, universal cells that could be transplanted to any recipient without requiring a matching donor could significantly enhance their therapeutic potential and accelerate clinical translation. To create off-the-shelf hypoimmunogenic cells, we used CRISPR-Cas9 to delete B2M (HLA class I) and CIITA (master regulator of HLA class II). Double-knockout (DKO) iPSC-derived neural progenitor cells (NPCs) evaded T-cell-mediated immune rejection in vitro and after grafting into the injured spinal cord of athymic rats and humanized mice. However, loss of HLA class I heightened susceptibility to host natural killer (NK) cell attack, limiting graft survival. To counter this negative effect, we engineered DKO NPCs to overexpress macrophage migration inhibitory factor (MIF), an NK cell checkpoint ligand. MIF expression markedly reduced NK cell-mediated cytotoxicity and improved long-term engraftment and integration of NPCs in the animal models for spinal cord injury. These findings demonstrate that MIF overexpression, combined with concurrent B2M and CIITA deletion, generates hiPSC neural derivatives that escape both T- and NK-cell surveillance. This strategy provides a scalable route to universal donor cells for regenerative therapies in SCI and potentially other disorders. Full article

Background: Human induced pluripotent stem cell cardiomyocytes (hiPSC-CMs) allow for high-throughput evaluation of cardiomyocyte (CM) physiology in health and disease. While multimodality testing provides a large breadth of information related to electrophysiology, contractility, and intracellular signaling in small populations of iPSC-CMs, current technologies for analyzing these parameters are expensive and resource-intensive. Methods: We have designed a novel 2D/3D hybrid organoid system that can harness optical imaging techniques to assess electromechanical properties and calcium dynamics across CMs in a high-throughput manner. We validated our methods using a doxorubicin-based system, as the drug has well-characterized cardiotoxic, pro-arrhythmic effects. Results: This novel hybrid system provides the functional benefit of 3D organoids while minimizing optical interference from multilayered cellular systems through our cell-culture techniques that propagate organoids outwards into 2D iPSC-CM sheets. The organoids recapitulate contractile forces that are more robust in 3D structures and connectivity, while 2D CMs facilitate analysis at an individual cellular level, which recreated numerous doxorubicin-induced electrophysiologic and propagation abnormalities. Conclusions: Thus, we have developed a novel 2D/3D hybrid organoid model that employs an integrated optical analysis platform to provide a reliable high-throughput method for studying cardiotoxicity, providing valuable data on calcium, contractility, and signal propagation. Full article

Alzheimer’s disease (AD), the leading cause of dementia, remains poorly understood despite decades of intensive research, which continues to hinder the development of effective treatments. As a complex multifactorial disorder, AD lacks a cure to halt the progressive neurodegeneration, and the precise mechanisms underlying its onset and progression remain elusive, limiting therapeutic options. Due to the challenges of studying neuronal cells in vivo, technologies such as clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) and human-induced pluripotent stem cells (hiPSCs) are key for identifying therapeutic targets, although they face technical and ethical hurdles in their early stages. CRISPR/Cas9 and hiPSCs are promising for disease modeling and therapy, but off-target effects and the complexity of gene editing in the brain limit their use. CRISPR technology enables specific genetic modifications in key AD-related genes, such as APP, PSEN1, PSEN2, and APOE, providing valuable insights into disease mechanisms. iPSC-derived neurons, astrocytes, microglia, and 3D organoids can recapitulate key aspects of human AD pathology, but they do not fully replicate the complexity of the human brain, limiting clinical applicability. These technologies advance studies of amyloid processing, tau aggregation, neuroinflammation, and oxidative stress, yet translating them into clinical therapies remains challenging. Despite the promise of CRISPR/Cas9 and iPSCs for precision medicine, gaps in knowledge about their long-term safety and efficacy must be addressed before clinical implementation. Full article

Protein-coated ultra-high viscosity (UHV)-alginate hydrogels are essential to mimic the physiological in vivo environment of humans in several in vitro applications. This work presents an optimized bioreactor-integrated freeze-drying process for Matrigel^TM-coated UHV-alginate microcarriers in the context of human induced pluripotent stem cell (hiPSC) expansion. The impact of freeze-drying on the UHV-alginate microcarriers using trehalose 100 mg/mL in 0.9% NaCl as a lyoprotective agent, as well as the stem cell response using hiPSCs, was analyzed using microscopy-based screenings. First observations of the process showed that the integrity of the cake was preserved in the samples with a maximum vapor exchanging rate. Following rehydration, the UHV-alginate microcarriers retained their original morphology. Upon the addition of Poloxamer 188, stickiness and bubble formation were reduced. The expansion of hiPSCs in a suspension bioreactor resulted in a 5–7-fold increase in total cell count, yielding at least 1.3 × 10⁷ cells with viability exceeding 80% after seven days of cultivation. In flow cytometry analysis, the pluripotency factors OCT3/4 and SSEA4 resulted in positive signals in over 98% of cells, while the differentiation factor SSEA1 was positive in fewer than 10% of cells. Supported by preceding in silico predictions of drying time, this study presents, for the first time, basic steps toward a “ready-to-use” bioreactor-integrated freeze-drying process for UHV-alginate microcarriers in the iPSC context. Full article

Oligodendrocyte precursor cells (OPCs) are a dynamic and heterogeneous population of glial cells essential for brain development and myelination. Beyond their well-established role in oligodendrogenesis, emerging evidence suggests that OPCs contribute to synaptic regulation, neuronal communication, and brain plasticity. Recent studies have increasingly implicated OPC dysfunction in the pathophysiology of psychiatric disorders, particularly schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD). This narrative review integrates clinical, genetic, transcriptomic, and histological findings to examine the role of OPC alterations in mental illnesses. In SCZ, OPC abnormalities predominantly affect myelination, but recent data also suggest deficits in non-canonical functions, including neuron–OPC communication. Findings in BD largely mirror those in SCZ, implying shared OPC-related mechanisms across these disorders. In contrast, OPC involvement in MDD appears more complex, with evidence supporting both myelination deficits and non-canonical dysfunctions, such as impaired neuro–glial interactions and perineuronal network alterations. The developmental timing of OPC dysfunction may represent a common denominator underlying psychiatric disorders, as early-life stress and neurodevelopmental disturbances have been linked to OPC impairments. Moreover, given the shared developmental origins of OPCs and parvalbumin-positive interneurons, disruptions in their mutual interactions may contribute to broader neural network dysregulation. Despite these insights, the field remains in its infancy. Future studies integrating independent human cohorts with robust preclinical models are needed to clarify the extent of OPC involvement in psychiatric pathophysiology. Understanding OPC dysfunction may reveal novel biomarkers and open new avenues for individualized therapeutic interventions and preventive strategies in mental health. Full article

Under chronic stress, the pro-arrhythmic effect and mechanism of circulating humoral factors in human cardiomyocytes remain unknown. In the present study, we observed the effect of serum from chronic-stress mice on the electrical activity of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Male C57/BL6J mice were subjected to 35 days of chronic unpredictable mild stress (CUMS). The serum from CUMS mice induced arrhythmia-like events (cell arrhythmias) in hiPSC-CMs in a time- and concentration-dependent manner. Patch clamp recordings in the heterologous expression system demonstrated that the serum derived from CUMS mice exerted an inhibitory effect on the cloned human potassium currents (I_to, I_Kr, I_Ks) that mediate action potential repolarization. In addition, serum from CUMS reduced the expression of relevant channel proteins. Moreover, both heat-inactivated serum and deproteinized serum evoked similar severity of cell arrhythmias in hiPSC-CMs as the untreated serum, indicating that circulating substances with small molecules were mainly involved in the occurrence of arrhythmias. Furthermore, metabolomics analysis showed that 90 small-molecule metabolites increased and 390 decreased in CUMS serum. We concluded that circulating humoral substances under chronic stress conditions have direct arrhythmogenic effects by inducing ion channel dysfunction in myocardial cells. Full article

Background/Objectives: Age-related macular degeneration (AMD) is the third leading cause of irreversible blindness in elderly individuals aged over 50 years old. Oxidative stress plays a crucial role in the etiopathogenesis of multifactorial AMD disease. The phospholipid bilayer EVs derived from the culture-conditioned medium of human induced pluripotent stem cell (hiPSC) differentiated retinal organoids aid in cell-to-cell communication, signaling, and extracellular matrix remodeling. The goal of the current study is to establish and evaluate the encapsulation of a hydrophobic compound, cannabidiol (CBD), into retinal organoid-derived extracellular vesicles (EVs) for potential therapeutic use in AMD. Methods: hiPSC-derived retinal organoid EVs were encapsulated with CBD via sonication (CBD-EVs), and structural features were elucidated using atomic force microscopy, nanoparticle tracking analysis, and small/microRNA (miRNA) sequencing. ARPE-19 cells and oxidative-stressed (H₂O₂) ARPE-19 cells treated with CBD-EVs were assessed for cytotoxicity, apoptosis (MTT assay), reactive oxygen species (DCFDA), and antioxidant proteins (immunohistochemistry and Western blot). Results: Distinct miRNA cargo were identified in early and late retinal organoid-derived EVs, implicating their roles in retinal development, differentiation, and functionality. The therapeutic effects of CBD-loaded EVs on oxidative-stressed ARPE-19 cells showed greater viability, decreased ROS production, downregulated expression of inflammation- and apoptosis-related proteins, and upregulated expression of antioxidants by Western blot and immunocytochemistry. Conclusions: miRNAs are both prognostic and predictive biomarkers and can be a target for developing therapy since they regulate RPE physiology and diseases. Our findings indicate that CBD-EVs could potentially alleviate the course of AMD by activating the targeted proteins linked to the adenosine monophosphate kinase (AMPK) pathway. Implicating the use of CBD-EVs represents a novel frontline to promote long-term abstinence from drugs and pharmacotherapy development in treating AMD. Full article

Human induced pluripotent stem cells (hiPSCs) hold great potential for regenerative medicine. However, optimizing their differentiation into specific lineages within three-dimensional (3D) scaffold-based culture systems that mimic in vivo environments remains challenging. This study examined the trilineage differentiation of hiPSCs under various 3D conditions using synthetic peptide hydrogel matrices with and without embryoid body (EB) medium induction. hiPSC 3D colonies (spheroids), naturally formed from single cells or small clusters in 3D culture, were used for differentiation into the three germ lineages. Differentiated spheroids exhibited distinct morphological characteristics and significantly increased expression of key lineage-specific markers—FOXA2 (endoderm), Brachyury (mesoderm), and PAX6 (ectoderm)—compared to undifferentiated controls. Marker expression varied depending on the 3D culture conditions. Differentiation efficiency improved significantly, increasing from 16% to 71% for endoderm, 61% to 80% for mesoderm, and 35% to 48% for ectoderm, by selecting the appropriate 3D matrix and applying EB induction. Comprehensive data analysis from RT-qPCR, immunocytochemistry staining, and flow cytometry confirmed that the Synthegel Spheroid (SGS) is a viable 3D matrix for evaluating all three germ lineages using a commercial trilineage differentiation kit. While EB induction is essential for endodermal differentiation, it is not required for mesodermal and ectodermal lineages. These findings are valuable not only for screening initial differentiation potential at the lineage level but also for optimizing 3D differentiation protocols for deriving somatic cells from hiPSCs. Full article

Background: Choroid plexus is a complex structure in the human brain that is responsible for the secretion of extracellular vesicles (EVs) in cerebrospinal fluid. Few studies to date have generated choroid plexus (ChP) organoids differentiated from human induced pluripotent stem cells (hiPSCs) and analyzed their secreted EVs. The scalable Vertical-Wheel bioreactors (VWBRs) provide low shear stress and a controlled environment. Methods: This study utilized VWBRs for the differentiation of hiPSCs into ChP organoids and generation of the secreted EVs compared to a static culture. Additionally, this study loaded curcumin into ChP organoid-derived EVs, performed EV lyophilization, and determined the ability of the re-hydrated EVs to alleviate neuro-inflammation. Results: The results demonstrated that the VWBR culture exhibited more aerobic metabolism and active glucose and glutamine consumption than the static control. Consequently, the ChP markers and Endosomal Sorting Complexes Required for Transport-dependent and -independent EV biogenesis genes were significantly upregulated (2–3-fold) in the VWBR, producing four-fold-higher EVs per mL media than the static control. The EVs retained similar size and zeta potential after lyophilization and re-hydration. The cells exposed to amyloid beta 42 oligomers and treated with the curcumin-loaded re-hydrated EVs showed high viability and the reduced inflammatory response determined by TNF-α and IL-6 expression. Conclusions: This study demonstrates a scalable bioreactor system to promote ChP organoid differentiation and generation of EV-based cell-free therapeutics to treat neural inflammation in various neurological disorders. Full article