Human embryo models hold great promise for advancing medicine, but current systems lack efficiency and fidelity in replicating post-implantation stages. Here, we investigate whether STAT3 activation can reprogram pluripo...Human embryo models hold great promise for advancing medicine, but current systems lack efficiency and fidelity in replicating post-implantation stages. Here, we investigate whether STAT3 activation can reprogram pluripotent stem cells (PSCs) into early fates that self-organize into embryo models. Using a medium enhancing STAT3 activity (SAM), PSCs reprogram within 60 h into hypoblast, trophectoderm, naive epiblast, and extraembryonic mesoderm. Dissociating SAM-treated PSCs at 60-120 h, followed by 3D culture, results in dynamic development of post-implantation embryo-like structures with up to 52.41% ± 8.92% efficiency. Resulting day 6 examples resemble Carnegie stages 5 (CS5) to 7 (CS7) embryos, exhibiting bilaminar disc structure with epiblast and yolk sac, amniotic cavity, mesenchyme, chorionic cavity, and trophoblast. Notably, CS6/7-like examples exhibit gastrulation, including the formation and correct positioning of primitive streak, epithelial-to-mesenchymal transition, mesoderm, and definitive endoderm. The STAT3-mediated embryo model also closely aligns molecularly with CS6/7 embryo references and represents a state-of-the-art platform for advancing human embryogenesis research.
Márquez-Valadez B, Gallardo-Caballero M, Llorens-Martín M
Cell Stem Cell
· 2025 Oct · PMID 40957417
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Adult hippocampal neurogenesis (AHN) regulates hippocampal-dependent functions and is targeted by physiological aging and neurodegenerative conditions. Patients with neuropsychiatric disorders show hippocampal abnormalit...Adult hippocampal neurogenesis (AHN) regulates hippocampal-dependent functions and is targeted by physiological aging and neurodegenerative conditions. Patients with neuropsychiatric disorders show hippocampal abnormalities that might be related to changes in AHN. Here, we sought to determine whether major depression, schizophrenia, and bipolar disorder threaten the integrity of human AHN and the homeostasis of the dentate gyrus (DG) neurogenic niche-a specialized microenvironment in which new neurons grow. Our results show that the initial and intermediate stages of AHN, as well as distinct components of the niche, are selectively affected in these disorders. Demographics and various lifestyle-related factors (such as the consumption of alcohol and drugs of abuse) modulate both AHN and the cells that compose the niche, not only in patients with these disorders but also in neurologically healthy control individuals. These data might be relevant for the design of future strategies to treat and prevent mental health conditions.
Pham J, Isquith J, Balaian L
… +26 more, Nandi SP, Engstrom C, Mack K, van der Werf I, Chang P, Stoudemire J, Ladel L, Klacking E, Ruiz A, Chilin-Fuentes D, Sneifer J, Mays D, Gamble P, Giza S, Janowitz J, Nienaber T, Mishra T, Khachatrian AA, Molina E, Snyder MP, Morris SR, Clements T, Muotri AR, Whisenant T, Alexandrov LB, Jamieson CHM
Cell Stem Cell
· 2025 Sep · PMID 40912236
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Human hematopoietic stem and progenitor cell (HSPC) fitness declines following exposure to stressors that reduce survival, dormancy, telomere maintenance, and self-renewal, thereby accelerating aging. While previous Nati...Human hematopoietic stem and progenitor cell (HSPC) fitness declines following exposure to stressors that reduce survival, dormancy, telomere maintenance, and self-renewal, thereby accelerating aging. While previous National Aeronautics and Space Administration (NASA) research revealed immune dysfunction in low-earth orbit (LEO), the impact of spaceflight on human HSPC aging had not been studied. To study HSPC aging, our NASA-supported Integrated Space Stem Cell Orbital Research (ISSCOR) team developed bone marrow niche nanobioreactors with lentiviral bicistronic fluorescent, ubiquitination-based cell-cycle indicator (FUCCI2BL) reporter for real-time HSPC tracking in artificial intelligence (AI)-driven CubeLabs. In month-long International Space Station (ISS) missions (SpX-24, SpX-25, SpX-26, and SpX-27) compared with ground controls, FUCCI2BL reporter, whole-genome and transcriptome sequencing, and cytokine arrays demonstrated cell-cycle, inflammatory cytokine, mitochondrial gene, human repetitive element, and apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3 (APOBEC3) deregulation together with clonal hematopoietic mutations. Furthermore, HSPC functionally organized multi-omics aging (HSPC-FOMA) analyses revealed reduced telomere maintenance, adenosine deaminase acting on RNA1 (ADAR1) p150 self-renewal gene expression, and replating capacity indicative of space-associated HSPC aging that may limit long-duration spaceflight.
Stem cells and organoids enable the modeling of various aspects of human development in vitro, yet integrating them to study maternal-fetal interactions remains challenging. In this review, we explore the current in vitr...Stem cells and organoids enable the modeling of various aspects of human development in vitro, yet integrating them to study maternal-fetal interactions remains challenging. In this review, we explore the current in vitro models of the endometrium, placenta, and embryo and identify key challenges associated with their integration, including the establishment of morpho-functional complexity, spatiotemporal coordination, and appropriate in vivo benchmarking. We propose an interdisciplinary perspective that emphasizes a shift from "building blocks" to "building interactions." Altogether, we provide a discussion on the challenges and prospects for advancing mechanistic understanding of intrauterine human development and the maternal-fetal interface.
As stem cell therapies make great strides in clinical trials, the challenge of immune rejection has come into a sharper focus. Several recent clinical reports provide insight into the challenges posed by HLA mismatch and...As stem cell therapies make great strides in clinical trials, the challenge of immune rejection has come into a sharper focus. Several recent clinical reports provide insight into the challenges posed by HLA mismatch and immunosuppression. Immunological analyses accompanying recent cell therapy trials suggest strategies that may mitigate these risks.
Fat depots across the body dynamically tune their sizes in response to nutrient demands and nonmetabolic cues. Writing in Cell Stem Cell, Rivera-Gonzalez et al. report that skin fat, notable for its ability to rapidly ex...Fat depots across the body dynamically tune their sizes in response to nutrient demands and nonmetabolic cues. Writing in Cell Stem Cell, Rivera-Gonzalez et al. report that skin fat, notable for its ability to rapidly expand, harbors molecularly distinct precursors, primed for proliferation and differentiation into mature adipocytes.
Dysfunction of A10 midbrain dopaminergic (mDA) neurons is linked to psychiatric disorders, such as depression. In this issue, Yan et al. present an efficient method for differentiating human pluripotent stem cells into A...Dysfunction of A10 midbrain dopaminergic (mDA) neurons is linked to psychiatric disorders, such as depression. In this issue, Yan et al. present an efficient method for differentiating human pluripotent stem cells into A10-like mDA neurons. Activation of grafted A10-like neurons into the mouse mesolimbic circuit alleviates depression-like symptoms.
While current stem cell differentiation protocols generate β cell-enriched islets that reverse hyperglycemia post-implantation, they can cause hypoglycemia. Meng et al. reconstruct endocrine subtype-complete islets, whic...While current stem cell differentiation protocols generate β cell-enriched islets that reverse hyperglycemia post-implantation, they can cause hypoglycemia. Meng et al. reconstruct endocrine subtype-complete islets, which restore counterregulatory responses and protect against hypoglycemia in diabetic mice, highlighting the importance of endocrine diversity in designing physiologically regulated cell therapies for diabetes.
CAR-T cell therapy is rapidly being extended to target various pathophysiological processes beyond cancer. In this issue of Cell Stem Cell, Zhao et al. engineered PDGFRβ-specific CAR-T cells in vivo to selectively target...CAR-T cell therapy is rapidly being extended to target various pathophysiological processes beyond cancer. In this issue of Cell Stem Cell, Zhao et al. engineered PDGFRβ-specific CAR-T cells in vivo to selectively target extracellular matrix-producing cells in kidney fibrosis, opening new opportunities for treating fibrotic diseases with precision immunotherapy.
The discrepancy between organoid and immortalized cell line cultures for cancer target discovery remains unclear. Here, our multi-tiered clustered regularly interspaced short palindromic repeats (CRISPR) screens reveal i...The discrepancy between organoid and immortalized cell line cultures for cancer target discovery remains unclear. Here, our multi-tiered clustered regularly interspaced short palindromic repeats (CRISPR) screens reveal in vivo-relevant metabolic dependencies and synthetic lethal pairs that can be uncovered with tumor organoids but not cell lines or even three-dimensional (3D) spheroids. These screens identify lanosterol synthase and acetyl-coenzyme A (CoA) carboxylase inhibitors as effective treatments that impede xenografted tumor growth in mice. These lipid metabolic inhibitors exhibit nanomolar half-maximal inhibitory concentration (IC) values across diverse human gastric cancer organoids resistant to first-line treatments. Mechanistically, gastric cancer organoids and in vivo tumors exhibit lipid metabolic adaptations not seen in two-dimensional (2D) in vitro cultures. Additionally, enteric neurons modulate lipid metabolism in tumor organoids, altering drug sensitivity by up to two orders of magnitude. A neuron-cocultured CRISPR screen further reveals that acetyl-CoA carboxylase expression determines lanosterol synthase inhibitor efficacy. These findings highlight the critical roles of organoid environment and neuronal interaction in cancer lipid reliance.
Cell Stem Cell
· 2025 Oct · PMID 40885193
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Early post-implantation human development is poorly understood due to limited access to natural embryos. Integrated stem cell-based embryo models (SCBEMs) offer an alternative, but current models face challenges in repro...Early post-implantation human development is poorly understood due to limited access to natural embryos. Integrated stem cell-based embryo models (SCBEMs) offer an alternative, but current models face challenges in reproducibility, efficiency, and genomic stability. Here, we developed inducible SCBEMs (iSCBEMs) by combining primed human pluripotent stem cells (hPSCs) with transgene-induced extraembryonic cells derived from naive hPSCs. iSCBEMs recapitulate several key features of early post-implantation development, including amniotic-, yolk sac-, and chorionic-like cavity formation, differentiation of syncytiotrophoblast-like cells forming lacunae, bilaminar disk formation, anterior-posterior axis establishment, and early gastrulation. Single-cell RNA sequencing revealed that iSCBEMs recapitulate key cell types and developmental transitions characteristic of Carnegie stage 5-6 (CS5-CS6) embryos. We further traced the origins of amnion-, yolk sac endoderm-, and extraembryonic mesoderm-like cells, providing insights into their developmental trajectories. Although imperfect, human iSCBEMs represent a robust and valuable model for studying early post-implantation development, overcoming the limitations of natural embryo accessibility.
Zhao S, Li R, Xia Y
… +17 more, Wang X, Liu Z, Chu Q, He J, Zhang J, Guo Y, Wang Y, Wu J, Zhang Y, Wang Z, Zhang Z, Zeng R, Zhang C, Lv J, Sun J, Tang W, Yi F
Kidney fibrosis is a hallmark of chronic kidney disease (CKD) and a potential therapeutic target. However, clinical interventions and therapies targeting kidney fibrosis remain conceptual and practical challenges due to...Kidney fibrosis is a hallmark of chronic kidney disease (CKD) and a potential therapeutic target. However, clinical interventions and therapies targeting kidney fibrosis remain conceptual and practical challenges due to the complex origin, functional heterogeneity, and regulation of scar-forming cells. Here, we define fibroblasts, pericytes, and myofibroblasts as the major extracellular matrix (ECM)-producing cells in the kidney, highlighting their primary contribution to kidney fibrosis. We then identify platelet-derived growth factor receptor β (PDGFRβ) as a potential targeting surface antigen for anti-fibrotic chimeric antigen receptor (CAR)-T against CKD. In multiple mouse CKD models, both adoptive transfer and CD5-lipid nanoparticle (LNP)-mediated in vivo generation of PDGFRβ CAR-T cells significantly ameliorate fibrosis-associated pathologies, including kidney, myocardial interstitial, and perivascular fibrosis without notable toxicity, evoking an integrated therapeutic strategy for multi-organ fibrosis in mice with CKD and its cardiovascular complications. The anti-fibrotic effects are also demonstrated in the human kidney organoid CKD, further strongly supporting the therapeutic potential for the treatment of patients with CKD.
Morizane A, Yamasaki E, Shindo T
… +17 more, Anazawa T, Sawamoto N, Shima A, Yamakado H, Nakanishi E, Sawamura M, Taruno Y, Doi D, Kikuchi T, Kawasaki Y, Saito MK, Kikuchi T, Arakawa Y, Miyamoto S, Nakamoto Y, Takahashi R, Takahashi J
Because the central nervous system (CNS) is an immune-privileged organ, it requires different immunosuppression strategies for cell therapies using induced pluripotent stem cells (iPSCs) compared with ones for organ tran...Because the central nervous system (CNS) is an immune-privileged organ, it requires different immunosuppression strategies for cell therapies using induced pluripotent stem cells (iPSCs) compared with ones for organ transplantations. We recently conducted the first in-human clinical trial of a cell therapy for Parkinson's disease using allogeneic iPSCs (jRCT number: jRCT2090220384). All patients were transplanted with dopaminergic neural progenitors differentiated from iPSCs (iPSC-DANs), which had homozygous human leukocyte antigen (HLA) haplotypes, through immunosuppression with tacrolimus alone. No clinically significant immune reaction was observed in this study, regardless of HLA compatibility. However, a highly sensitive mixed lymphocyte reaction using iPSC-derived dendritic cells as a stimulator demonstrated the activation of lymphocytes from HLA-mismatch-grafted recipients. This finding suggests that the low expression of HLA in iPSC-DANs contributes to successful engraftment in the immune-privileged CNS. These results indicate that only moderate immunosuppressive treatment may be required for stem cell transplantation to the CNS.
Griffin M, Guo JL, Parker JBL
… +13 more, Kuhnert M, Li DJ, Valencia C, Morgan A, Downer M, Cotterell AC, Lu JM, Dilorio S, Bauer-Rowe Ramos KE, Januszyk M, Chang HY, Wan DC, Longaker MT
Cell Stem Cell
· 2025 Sep · PMID 40816279
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Skin fibrosis is driven by fibroblast activation and excessive extracellular matrix deposition. To ascertain the fibroblast subpopulation(s) responsible for instigating fibrosis, we employed an established murine bleomyc...Skin fibrosis is driven by fibroblast activation and excessive extracellular matrix deposition. To ascertain the fibroblast subpopulation(s) responsible for instigating fibrosis, we employed an established murine bleomycin skin fibrosis model. We characterized both the fibrotic and remodeling phases of dermal fibrosis through a multi-omic approach. Using an unsupervised machine learning algorithm that quantifies 294 fiber features, we identified precise time points of fibrosis and regeneration. Single-cell transcriptomic and epigenomic sequencing then identified a Cyp26b1-expressing fibroblast subpopulation responsible for dermal fibrosis. The same fibroblast subtype was mapped to Visium spatial transcriptomic data. We further mapped the fibrotic subtypes to protein spatial data. To ascertain the functional impact of the fibroblast subpopulations, transplant delivery analysis showed their ability to drive skin fibrosis. Lastly, we identified a small molecular inhibitor of Cyp26b1 (talarozole) that prevents and rescues dermal fibrosis. Conclusively, we establish an atlas of the fibrotic and regenerative biological drivers of skin fibrosis.
Li Y, Tang S, Wang H
… +19 more, Zhu H, Lu Y, Zhang Y, Guo S, He J, Li Y, Zhang Y, Shi X, Miao Y, Zhong C, Zhu Y, Ju Y, Liu Y, Sun M, Wang Y, Chen L, Zhou H, Jin G, Gao D
Chemotherapy remains the primary treatment for pancreatic ductal adenocarcinoma (PDAC), but most patients ultimately develop resistance. Here, we established 260 pancreatic cancer organoid lines, followed by extensive mu...Chemotherapy remains the primary treatment for pancreatic ductal adenocarcinoma (PDAC), but most patients ultimately develop resistance. Here, we established 260 pancreatic cancer organoid lines, followed by extensive multi-omics profiling and therapeutic sensitivity assessments. Integrated analyses uncovered 6 novel coding and 35 noncoding driver candidates. We discovered 2,794 multi-omics features associated with drug sensitivity and 322 features linked to radiation sensitivity. Pharmacogenomic analyses revealed that chemoresistant organoids exhibited enrichment in protein glycosylation and cholesterol metabolism pathways. Notably, statins effectively targeted chemoresistant PDAC organoids. Statin treatment attenuated protein glycosylation, cholesterol levels, and the epithelial-to-mesenchymal transition (EMT) signature in PDAC organoids. We conducted a single-center, single-arm, phase 2 clinical trial (NCT06241352) combining atorvastatin with chemotherapy in patients with advanced pancreatic cancer. Among 37 patients, 26 (70.3%) demonstrated a response, with tumor markers decreasing by more than 20%, suggesting durable responses and potential clinical benefits in this challenging patient population.
Off-the-shelf CAR T cells need to reliably escape allogeneic immune responses to become universal medicines. The primary T cell product SC291 was engineered with a CD19 CAR, T cell receptor alpha constant (TRAC) knockout...Off-the-shelf CAR T cells need to reliably escape allogeneic immune responses to become universal medicines. The primary T cell product SC291 was engineered with a CD19 CAR, T cell receptor alpha constant (TRAC) knockout, and the hypoimmune (HIP) edits of HLA depletion and CD47 overexpression. Here, we report exploratory immune analyses from the ARDENT (NCT05878184) and GLEAM (NCT06294236) trials with HIP-edited CD19 CAR T cells. Although there was an alloimmune response against HLA-replete subpopulations of SC291, we observed no de novo immune response against fully edited HIP CAR T cells in all patients, irrespective of the dose or the patient's disease. The lack of antibodies against the HLA-replete CAR T cells was identified as a marker for deep tissue CD19 cell depletion, and all patients without such antibodies for 60 days showed concomitant B cell depletion in peripheral blood. The immune data presented support the reliability of the HIP concept to evade allorejection.
A10 dopaminergic neurons located in the ventral tegmental area play central roles in reward-related and goal-directed behaviors and are proposed to be target cells for treatment of various psychiatric disorders, includin...A10 dopaminergic neurons located in the ventral tegmental area play central roles in reward-related and goal-directed behaviors and are proposed to be target cells for treatment of various psychiatric disorders, including depression. Here, we report an efficient differentiation method to generate A10-like midbrain dopaminergic (mDA) neurons from human pluripotent stem cells (hPSCs) and found that post-mitotic patterning by Notch inhibitor, glial cell line-derived neurotrophic factor (GDNF), and ascorbic acid (AA) induced A10 subtype specification. These hPSC-derived mDA neurons exhibited characteristics of the A10 subtype, including gene expression profiles and electrophysiological properties. Moreover, grafted A10-like mDA neurons specifically project to their endogenous target brain regions and induce the anxiolytic phenotype in normal mice or antidepressant-like phenotypes in depression model mice. These results indicate that grafted A10-like mDA neurons can reconstruct specific circuits and functionally restore impaired circuits, highlighting the promising application of hPSC-derived neuron subtypes in the treatment of neuropsychiatric disorders.
Transplantation of pluripotent stem cell-derived islets (PSC-islets), containing functional insulin-producing β cells, represents promising cell therapy for restoring glycemic control in diabetes. However, recapitulation...Transplantation of pluripotent stem cell-derived islets (PSC-islets), containing functional insulin-producing β cells, represents promising cell therapy for restoring glycemic control in diabetes. However, recapitulation of complete endocrine composition in PSC-islets remains challenging, and their ability to counteract hazardous hypoglycemia, crucial to metabolic safety in vivo, remains unexplored. Here, we report robust generation of non-β cells in vitro. By incorporating non-β and β cells, we report reconstruction of PSC-islets comprising all five (α, β, δ, ε, and γ) endocrine subtypes (reconstructed PSC-islets). After reversal of hyperglycemia in diabetic mouse models, these islets exhibited robust protection against hypoglycemia, with only 3% of measurements falling below 54 mg/dL compared with 59% in non-reconstructed controls. Remarkably, hypoglycemic clamp assays suggested restoration of previously defective counterregulatory response in reconstructed PSC-islet recipients. These findings establish a strategy to control relative abundance of PSC-islet subtypes, providing a basis for calibrating post-transplant glycemic homeostasis with definitive hypoglycemic protection.
Yilmaz A, Gurhan G, Comar MY
… +32 more, Viukov S, Serfaty I, Gayretli M, Golenchenko S, Lokshtanov D, Ashouokhi S, Polanco A, Berlad I, Ha TW, Aguilera-Castrejon A, Tarazi S, Cohen M, Livnat N, Kumar K, Cholakkal H, Levy N, Yosef N, Khatib N, Kakun RR, Kedmi M, Nachman IB, Keren-Shaul H, Addadi Y, Orenbuch AH, Korovin K, Molchadsky A, Hochedlinger K, Gafni O, Maza I, Novershtern N, Oldak B, Hanna JH
The generation of post-gastrulation stem cell-derived mouse embryo models (SEMs) exclusively from naive embryonic stem cells (nESCs) has underscored their ability to give rise to embryonic and extra-embryonic lineages. H...The generation of post-gastrulation stem cell-derived mouse embryo models (SEMs) exclusively from naive embryonic stem cells (nESCs) has underscored their ability to give rise to embryonic and extra-embryonic lineages. However, existing protocols for mouse SEMs rely on the separate induction of extra-embryonic lineages and on ectopic expression of transcription factors to induce nESC differentiation into trophectoderm (TE) or primitive endoderm (PrE). Here, we demonstrate that mouse nESCs and naive induced pluripotent stem cells (niPSCs) can be simultaneously co-induced, via signaling pathway modulation, to generate PrE and TE extra-embryonic cells that self-organize into embryonic day (E) 8.5-E8.75 transgene-free (TF) SEMs. We also devised an alternative condition (AC) naive media that in vitro stabilizes TF-SEM-competent OCT4+/NANOG+ nESC colonies that co-express antagonistic CDX2 and/or GATA6 extra-embryonic fate master regulators and self-renew while remaining poised for TE and PrE differentiation, respectively. These findings improve mouse SEM strategies and shed light on amplifying an inherent and dormant extra-embryonic plasticity of mouse naive pluripotent cells in vitro.