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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

Pancreatic β cells derived from human induced pluripotent stem cells (hiPSCs) represent a promising therapeutic avenue in regenerative medicine for diabetes treatment. However,current differentiation protocols lack the specificity and efficiency required to reliably produce fully functional β cells,limiting their clinical applicability. Epigenetic barriers,such as histone modifications,may hinder proper differentiation and the acquisition of essential maturation markers in these cells. Methods: hiPSCs were cultured under feeder-free conditions and subjected to lentiviral transduction with shRNA constructs to silence KDM4A. Differentiation into pancreatic β-like cells was performed using stepwise protocols,with or without doxycycline supplementation,to evaluate the effect of KDM4A suppression. Gene expression was quantified by RT-qPCR,protein expression was assessed by western blotting and immunofluorescence,and functional insulin release was determined by glucose-stimulated insulin secretion (GSIS) assays. Statistical analysis was conducted using unpaired two-tailed Student’s t-tests,with significance set at p < 0.05. Results: A reduction in pancreatic development proteins was observed in the different differentiation states evaluated,after blocking KDM4A expression. Knockdown of KDM4A significantly reduced the expression of pancreatic β-cell genes,such as PDX1,Nkx6.1,and Ins,by 50% compared to WT iPSCs differentiated under the same conditions. Similarly,glucose-stimulated insulin secretion was reduced by approximately 80% in KDM4A-deficient β-like cells. Conclusions: These results emphasize the critical role of histone demethylation in hiPSC differentiation toward β cells. Our findings identify KDM4A as a key epigenetic regulator,suggesting that its modulation could enhance the generation of functional β cells for regenerative medicine in diabetes. View Publication

Gastrointestinal (GI) dysfunction,characterized by severe diarrhea and dehydration,is a central contributor to morbidity and mortality in filovirus disease in patients,yet the role of the epithelium in this clinical outcome remains poorly defined. Here,we employ induced pluripotent stem cell (iPSC)-derived human intestinal (HIOs) and colonic organoids (HCOs) to model Ebola virus (EBOV) and Marburg virus (MARV) infection. These organoids are permissive to filovirus infection and support viral replication. Bulk RNA sequencing revealed distinct intestinal and colonic epithelial responses,including apical and junctional disruption and a delayed virus-specific induction of interferon-stimulated genes. Moreover,infection impaired adenylate cyclase signaling and CFTR-mediated ion transport,providing mechanistic insight into virus-induced secretory diarrhea. This platform recapitulates key features of human GI pathology in filoviral disease and serves as a powerful system to dissect host-pathogen interactions and identify therapeutic targets. Author summaryEbola virus (EBOV) and Marburg virus (MARV) are among the most lethal viruses known. Infection with these viruses leads to severe disease and death. One of their most harmful effects is damage to the gastrointestinal tract,causing intense diarrhea and life-threatening dehydration. Yet,how these viruses affect the gut remains poorly understood. In this study,we used human mini-guts—small,three-dimensional tissues grown from stem cells that mimic the human intestinal and colonic epithelium—to investigate how these viruses interact with gut epithelial cells. We found that both EBOV and MARV infect and replicate in these tissues,disrupt key barrier structures,and interfere with the cells’ ability to regulate fluid secretion. These effects mirror the severe symptoms seen in patients. Our study provides new insight into how EBOV and MARV damage the gut and identifies specific cellular pathways that may be targeted for treatment. This research not only improves our understanding of EBOV and MARV infections but also offers new infection platforms for testing therapies aimed at protecting the gastrointestinal system during filovirus outbreaks. View Publication

UNLABELLED Among the known genetic risk factors for Parkinson disease,mutations in GBA1,the gene responsible for the lysosomal disorder Gaucher disease,are the most common. This genetic link has directed attention to the role of the lysosome in the pathogenesis of parkinsonism. To study how glucocerebrosidase impacts parkinsonism and to evaluate new therapeutics,we generated induced human pluripotent stem cells from four patients with Type 1 (non-neuronopathic) Gaucher disease,two with and two without parkinsonism,and one patient with Type 2 (acute neuronopathic) Gaucher disease,and differentiated them into macrophages and dopaminergic neurons. These cells exhibited decreased glucocerebrosidase activity and stored the glycolipid substrates glucosylceramide and glucosylsphingosine,demonstrating their similarity to patients with Gaucher disease. Dopaminergic neurons from patients with Type 2 and Type 1 Gaucher disease with parkinsonism had reduced dopamine storage and dopamine transporter reuptake. Levels of α-synuclein,a protein present as aggregates in Parkinson disease and related synucleinopathies,were selectively elevated in neurons from the patients with parkinsonism or Type 2 Gaucher disease. The cells were then treated with NCGC607,a small-molecule noninhibitory chaperone of glucocerebrosidase identified by high-throughput screening and medicinal chemistry structure optimization. This compound successfully chaperoned the mutant enzyme,restored glucocerebrosidase activity and protein levels,and reduced glycolipid storage in both iPSC-derived macrophages and dopaminergic neurons,indicating its potential for treating neuronopathic Gaucher disease. In addition,NCGC607 reduced α-synuclein levels in dopaminergic neurons from the patients with parkinsonism,suggesting that noninhibitory small-molecule chaperones of glucocerebrosidase may prove useful for the treatment of Parkinson disease. SIGNIFICANCE STATEMENT Because GBA1 mutations are the most common genetic risk factor for Parkinson disease,dopaminergic neurons were generated from iPSC lines derived from patients with Gaucher disease with and without parkinsonism. These cells exhibit deficient enzymatic activity,reduced lysosomal glucocerebrosidase levels,and storage of glucosylceramide and glucosylsphingosine. Lines generated from the patients with parkinsonism demonstrated elevated levels of α-synuclein. To reverse the observed phenotype,the neurons were treated with a novel noninhibitory glucocerebrosidase chaperone,which successfully restored glucocerebrosidase activity and protein levels and reduced glycolipid storage. In addition,the small-molecule chaperone reduced α-synuclein levels in dopaminergic neurons,indicating that chaperoning glucocerebrosidase to the lysosome may provide a novel therapeutic strategy for both Parkinson disease and neuronopathic forms of Gaucher disease. View Publication

Accurate modeling of human neuronal cell biology has been a long-standing challenge. However,methods to differentiate human induced pluripotent stem cells (iPSCs) to neurons have recently provided experimentally tractable cell models. Numerous methods that use small molecules to direct iPSCs into neuronal lineages have arisen in recent years. Unfortunately,these methods entail numerous challenges,including poor efficiency,variable cell type heterogeneity,and lengthy,expensive differentiation procedures. We recently developed a new method to generate stable transgenic lines of human iPSCs with doxycycline-inducible transcription factors at safe-harbor loci. Using a simple two-step protocol,these lines can be inducibly differentiated into either cortical (i3 Neurons) or lower motor neurons (i3 LMN) in a rapid,efficient,and scalable manner (Wang et al.,2017). In this manuscript,we describe a set of protocols to assist investigators in the culture and genetic engineering of iPSC lines to enable transcription factor-mediated differentiation of iPSCs into i3 Neurons or i3 LMNs,and we present neuronal culture conditions for various experimental applications. {\textcopyright} 2018 by John Wiley & Sons,Inc. View Publication

Nonhuman primate (NHP) models are more predictive than rodent models for developing induced pluripotent stem cell (iPSC)-based cell therapy,but robust and reproducible NHP iPSC-cardiomyocyte differentiation protocols are lacking for cardiomyopathies research. We developed a method to differentiate integration-free rhesus macaque iPSCs (RhiPSCs) into cardiomyocytes with {\textgreater}85{\%} purity in 10 days,using fully chemically defined conditions. To enable visualization of intracellular calcium flux in beating cardiomyocytes,we used CRISPR/Cas9 to stably knock-in genetically encoded calcium indicators at the rhesus AAVS1 safe harbor locus. Rhesus cardiomyocytes derived by our stepwise differentiation method express signature cardiac markers and show normal electrochemical coupling. They are responsive to cardiorelevant drugs and can be successfully engrafted in a mouse myocardial infarction model. Our approach provides a powerful tool for generation of NHP iPSC-derived cardiomyocytes amenable to utilization in basic research and preclinical studies,including in vivo tissue regeneration models and drug screening. View Publication