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

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

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.

Microglia are the immune cells in the central nervous system (CNS) and become pro-inflammatory/activated in Alzheimer’s disease (AD). Cell surface glycosylation plays an important role in immune cells; however, the N-glycosylation and glycosphingolipid (GSL) signatures of activated microglia are poorly understood. Here, we study comprehensively combined transcriptomic and glycomic profiles using human induced pluripotent stem cells-derived microglia (hiMG). Distinct changes in N-glycosylation patterns in amyloid-? oligomer (A?O) and LPS-treated hiMG were observed. In A?O-treated cells, the relative abundance of bisecting N-acetylglucosamine (GlcNAc) N-glycans decreased, corresponding with a downregulation of MGAT3. The sialylation of N-glycans increased in response to A?O, accompanied by an upregulation of genes involved in N-glycan sialylation (ST3GAL4 and 6). Unlike A?O-induced hiMG, LPS-induced hiMG exhibited a decreased abundance of complex-type N-glycans, aligned with downregulation of mannosidase genes (MAN1A1, MAN2A2, and MAN1C1) and upregulation of ER degradation related-mannosidases (EDEM1-3). Fucosylation increased in LPS-induced hiMG, aligned with upregulated fucosyltransferase 4 (FUT4) and downregulated alpha-L-fucosidase 1 (FUCA1) gene expression, while sialofucosylation decreased, aligned with upregulated neuraminidase 4 (NEU4). Inhibition of sialylation and fucosylation in A?O- and LPS-induced hiMG alleviated pro-inflammatory responses. However, the GSL profile did not exhibit significant changes in response to A?O or LPS activation, at least in the 24-hour stimulation timeframe. A?O- and LPS- specific glycosylation changes could contribute to impaired microglia function, highlighting glycosylation pathways as potential therapeutic targets for AD.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-96596-1.

IntroductionNeuroinflammation is a key contributor to the pathogenesis of Alzheimer's disease (AD), and impaired clearance of amyloid-? (A?) by microglia is closely associated with disease progression. Oxytocin (OXT), a hypothalamic neuropeptide, has recently been reported to exert anti-inflammatory effects on microglia; however, its therapeutic potential in the human brain remains unclear.MethodsWe generated human cerebral organoids (hCOs) from induced pluripotent stem cells (iPSCs) to model early AD-like pathology. A? toxicity was induced by applying 3 ?M A?1–42 for 48 h. The protective effects of OXT were evaluated through immunohistochemistry, RT-qPCR, calcium imaging, and multielectrode array (MEA) recordings. The involvement of microglia in A? clearance was assessed by immunostaining and gene expression analysis of TREM2.ResultsA? exposure led to significant deposition of A? in the outer layers of hCOs, accompanied by suppressed neural activity and increased apoptotic signaling. Pretreatment with OXT attenuated A? deposition and caspase-3-mediated apoptosis in a concentration-dependent manner. OXT also restored calcium oscillations and neuronal network activity as measured by MEA. Notably, OXT enhanced the recruitment of microglia to A? deposits and upregulated the expression of TREM2, a key regulator of microglial phagocytosis. Co-expression of oxytocin receptors (OXTR) on Iba1-positive microglia suggests that OXT directly modulates microglial activation and A? clearance.ConclusionsOXT has neuroprotective effects on human cortical organoids by preserving their neuronal activity and promoting microglial-mediated A? clearance. This study provides novel insights into the therapeutic potential of OXT for targeting neuroinflammation and A? pathology in patients with AD. Graphical abstractImage 1 Highlights•Oxytocin reduces A? deposition and apoptosis in human cerebral organoids.•A? impairs neuronal activity, rescued by oxytocin preconditioning.•Oxytocin enhances microglial phagocytosis via OXTR and TREM2 upregulation.•Human iPSC-derived organoids model early A? pathology and oxytocin response.

Malaria caused by Plasmodium falciparum infection results in severe complications including cerebral malaria (CM), in which approximately 30% of patients end up with neurological sequelae. Sparse in vitro cell culture-based experimental models which recapitulate the molecular basis of CM in humans has impeded progress in our understanding of its etiology. This study employed healthy human induced pluripotent stem cells (iPSCs)-derived neuronal cultures stimulated with hemozoin (HMZ) - the malarial toxin as a model for CM. Secretome, qRT-PCR, Metascape, and KEGG pathway analyses were conducted to assess elevated proteins, genes, and pathways. Neuronal cultures treated with HMZ showed enhanced secretion of interferon-gamma (IFN-?), interleukin (IL)1-beta (IL-1?), IL-8 and IL-16. Enrichment analysis revealed malaria, positive regulation of cytokine production and positive regulation of mitogen-activated protein kinase (MAPK) cascade which confirm inflammatory response to HMZ exposure. KEGG assessment revealed up-regulation of malaria, MAPK and neurodegenerative diseases-associated pathways which corroborates findings from previous studies. Additionally, HMZ induced DNA damage in neurons. This study has unveiled that exposure of neuronal cultures to HMZ, activates molecules and pathways similar to those observed in CM and neurodegenerative diseases. Furthermore, our model is an alternative to rodent experimental models of CM.

BackgroundPhenotypically unstable Schwann cell-like cells (SCLCs), derived from mesenchymal stem cells (MSCs) require intercellular contact-mediated cues for Schwann cell (SCs)-fate commitment. Although rat dorsal root ganglion (DRG) neurons provide contact-mediated signals for the conversion of SCLCs into fate-committed SCs, the use of animal cells is clinically unacceptable. To overcome this problem, we previously acquired human induced pluripotent stem cell-derived sensory neurons (hiPSC-dSNs) as surrogates of rat DRG neurons that committed rat bone marrow SCLCs to the SC fate. In this study, we explored whether hiPSC-dSNs could mimic rat DRG neuron effects to obtain fate-committed SCs from hBMSC-derived SCLCs.MethodshiPSCs were induced into hiPSC-dSNs using a specific chemical small molecule combination. hBMSCs were induced into hBMSC-derived SCLCs in a specific culture medium and then co-cultured with hiPSC-dSNs to generate SCs. The identity of hBMSC-derived SCs (hBMSC-dSCs) was examined by immunofluorescence, western bolt, electronic microscopy, and RNA-seq. Immunofluorescence was also used to detect the myelination capacity. Enzyme-linked immunosorbent assay and neurite outgrowth analysis were used to test the secretion of neurotrophic factors.ResultsThe hBMSC-dSCs exhibited bi-/tri-polar morphology of SCs and maintained the expression of the SC markers S100, p75NTR, p0, GFAP, and Sox10, even after withdrawing the glia-inducing factors or hiPSC-dSNs. Electronic microscopy and RNA-seq analysis provided evidence that hBMSC-dSCs were similar to the original human SCs in terms of their function and a variety of characteristics. Furthermore, these cells formed MBP-positive segments and secreted neurotrophic factors to facilitate the neurite outgrowth of Neuro2A.ConclusionsThese results demonstrated that phenotypically stable and functionally mature hBMSC-dSCs were generated efficiently via the co-culture of hiPSC-dSNs and hBMSC-derived SCLCs. Our findings may provide a promising protocol through which stable and fully developed hBMSC-dSCs can be used for transplantation to regenerate myelin sheath.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1186/s13287-025-04217-5.

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.

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.

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.

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.

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.