Stem Cell Reviews and Reports

In Vitro Spermatogenesis on Human Decellularized Testicular Matrix Plates Following Exosome Treatment in a Dynamic Culture System
Hashemi E, Movahedin M, Ghiaseddin A and Aghamir SMK
Testicular tissue engineering for in vitro spermatogenesis aims to restore fertility, focusing on challenges like efficiency, ethical concerns, and the need for a deeper biological understanding. The use of decellularized scaffolds led to better cell seeding and differentiation, and exosomes led to enhanced spermatogenesis. Also, the dynamic culture systems are being explored to replicate in vivo conditions more accurately. In this study, we aimed to utilize a perfusion mini-bioreactor for the dynamic culture of mouse spermatogonial stem cells on decellularized testicular matrix plates supplemented with exosomes. Our goal was to assess the progression of the spermatogenesis process through histological, immunohistochemical, and molecular analyses over four weeks. Human testicular tissues were decellularized using 1% sodium dodecyl sulfate and were then fabricated into thin plates using a cryostat. Sertoli and spermatogonial stem cells were isolated from neonate mouse testis and seeded onto the decellularized testicular matrix plates. A mini-perfusion bioreactor was employed to create dynamic culture conditions. Also, MSCs-derived exosomes were introduced to the culture medium, alone or in combination with a spermatogenic medium containing numerous chemical factors. The histological, IHC, and molecular analyses were performed at the end of the experiment. Our decellularization procedure successfully preserved the ECM components, while eliminating native cells. The isolated cells expressed PLZF and VIMENTIN markers, confirming the presence of SSCs and Sertoli cells. The seeded scaffolds exhibited proper homing, viability, proliferation, and differentiation of the cells towards in vitro spermatogenesis. Also, exosome treatment is capable of enhancing the spermatogenic potential of SSCs. Our findings indicate that the dynamic culture system significantly promoted the proliferation and differentiation of SSCs into mature spermatozoa. The use of exosomes further enhanced these effects, as evidenced by improved cellular viability, reduced apoptosis, and advanced spermatogenesis to the elongated spermatid stage. The combined treatment of exosomes and spermatogenic medium showed a synergistic effect, yielding superior outcomes in terms of sperm cell maturity and functionality. This study underscores the potential of combining decellularized testicular matrices with exosome therapy in a dynamic culture set up to advance the field of reproductive biology and fertility restoration.
Unleashing the Power of Induced Pluripotent stem Cells in in vitro Modelling of Lesch-Nyhan Disease
Javed S, Fersini M and Bernardini G
Lesch-Nyhan disease (LND) is a monogenic rare neurodevelopmental disorder caused by a deficiency in hypoxanthine-guanine phosphoribosyltransferase (HPRT), the key enzyme of the purines salvage pathway. Beyond its well-documented metabolic consequences, HPRT deficiency leads to a distinctive neurobehavioral syndrome characterized by motor disabilities, cognitive deficits, and self-injurious behavior. Although various cell and animal models have been developed to investigate LND pathology, none have adequately elucidated the underlying mechanisms of its neurological alterations. Recent advances in human pluripotent stem cell research and in vitro differentiation techniques have ushered in a new era in rare neurodevelopmental disorders research. Pluripotent stem cells, with their ability to propagate indefinitely and to differentiate into virtually any cell type, offer a valuable alternative for modeling rare diseases, allowing for the detection of pathological events from the earliest stages of neuronal network development. Furthermore, the generation of patient-derived induced pluripotent stem cells using reprogramming technology provides an opportunity to develop a disease-relevant model within the context of a patient-specific genome. In this review, we examine current stem cell-based models of LND and assess their potential as optimal models for exploring key pathological molecular events during neurogenesis and for the discovering novel treatment options. We also address the limitations, challenges, and future prospects for improving the use of iPSCs in LND research.
Enhancing Late Retinopathy of Prematurity Outcomes with Fresh Bone Marrow Mononuclear Cells and Melatonin Combination Therapy
Mirnia K, Bitaraf M, Namakin K, Azimzadeh A, Tanourlouee SB, Zolbin MM, Masoumi A and Kajbafzadeh AM
Retinopathy of prematurity (ROP) is a vasoproliferative disease affecting premature neonates with life-lasting impacts. This study aims to investigate the long-term functional outcomes and alterations in neural retina architecture following the intravitreal transplantation of bone marrow mononuclear cells (BMMNC) in the rat models of ROP, and to evaluate the effect of adjunctive therapy with melatonin.
LNK/SH2B3 Loss Exacerbates the Development of Myeloproliferative Neoplasms in CBL-deficient Mice
Chen Y, Gong S, Tang J, Wang X, Gao Y, Yang H, Chen W, Hu H, Tong W and Lv K
Genetic variations of signaling modulator protein LNK (also called SH2B3) are associated with relatively mild myeloproliferative phenotypes in patients with myeloproliferative neoplasms (MPN). However, these variations can induce more severe MPN disease and even leukemic transformation when co-existing with other driver mutations. In addition to the most prevalent driver mutation JAK2V617F, LNK mutations have been clinically identified in patients harboring CBL inactivation mutations, but its significance remains unclear. Here, using a transgenic mouse model, we demonstrated that mice with the loss of both Lnk and Cbl exhibited severe splenomegaly, extramedullary hematopoiesis and exacerbated myeloproliferative characteristics. Moreover, a population of Mac1 myeloid cells expressed c-Kit in aged mice. Mechanistically, we discovered that LNK could pull down multiple regulatory subunits of the proteosome. Further analysis confirmed a positive role of LNK in regulating proteasome activity, independent of its well-established function in signaling transduction. Thus, our work reveals a novel function of LNK in coordinating with the E3 ligase CBL to regulate myeloid malignancies.
Model Organoids: Integrated Frameworks for the Next Frontier of Healthcare Advancements
Bhattacharya R, Bose D, Kaur T, Patel R, Renuka O and Rodriguez RV
The morphogenetic events leading to tissue formation can be recapitulated using organoids, which allows studying new diseases and modelling personalized medicines. In this review, culture systems comparable to human organs are presented, these organoids are created from pluripotent stem cells or adult stem cells. The efficient and reproducible models of human tissues are discussed for biobanking, precision medicine and basic research. Mechanisms used by these model systems with an overview of models from human cells are also covered. As human physiology is different from animals, culture conditions and tissue limits often become challenging. Organoids offer novel approaches for such cases with rapid screening, transplantation studies and in immunotherapy. Discrepancies with large datasets can be handled with an integrated framework of artificial intelligence or AI and machine learning. An attempt has been made to show the improved effectiveness, simplified iterations, along with image analysis that are possible from this synergy. AI-assisted organoids have the potential to transform healthcare by improving disease understanding and accelerating clinical decision-making through personalized and precision medicine.
Dental Pulp Stem Cell Conditioned Medium Enhance Osteoblastic Differentiation and Bone Regeneration
Chouaib B, Desoutter A, Cuisinier F and Collart-Dutilleul PY
Cell-free approaches, utilizing mesenchymal stem cell secretome, have promising prospects in various fields of regenerative medicine. In this study, we examined in vitro and in vivo the potential of dental pulp stem cell-conditioned medium (DPSC-CM) for bone regeneration.
BMSC Derived Exosomes Attenuate Apoptosis of Temporomandibular Joint Disc Chondrocytes in TMJOA via PI3K/AKT Pathway
Chen W, Huang F, Chen B, Lin H, Luo G, Zhang W, Zhang X, Zheng B, Wang Z, Wei S, He J and Liu C
Bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exos) are crucial means of intercellular communication and can regulate a range of biological processes by reducing inflammation, decreasing apoptosis and promoting tissue repair. We treated temporomandibular joint (TMJ) disc chondrocytes with TNF-α and performed local injection of sodium iodoacetate (MIA) in the TMJ of rats to establish in vitro and in vivo models of TMJ osteoarthritis (TMJOA). BMSC-Exos were isolated and extracted to evaluate their proliferation and trilineage differentiation abilities, and their antiapoptotic and chondroprotective effects were assessed. This study revealed that BMSC-Exos can be endocytosed by TMJ disc chondrocytes in vitro and that BMSC-Exos pretreatment strongly attenuated the inhibitory effect of TNF-α on the proliferative and chondrogenic potential of TMJ disc chondrocytes. The administration of BMSC-Exos significantly suppressed TNF-α-induced apoptosis in TMJ disc chondrocytes by increasing the phosphorylation level of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB/AKT) pathway-related proteins, whereas the PI3K inhibitor LY294002 neutralized this antiapoptotic effect. Intradiscal injection of BMSC-Exos alleviated the degeneration and inflammation of TMJ discs in a rat model of TMJOA. Our study revealed that BMSC-Exos can attenuate the apoptosis of TMJ disc chondrocytes and destruction of TMJ discs partially by inhibiting the apoptotic pathway and activating the PI3K/AKT pathway, thereby providing a promising treatment strategy for the regeneration of damaged TMJ discs.
Harnessing the Anti-Inflammatory Effects of Perinatal Tissue Derived Therapies for the Treatment of Inflammatory Skin Diseases: A Comprehensive Review
Khalilzad MA, Mohammadi J, Najafi S, Amirsaadat S, Zare S, Khalilzad M, Shamloo A, Khaghani A, Peyrovan A, Khalili SFS, Fayyaz N and Zare S
Dealing with chronic inflammatory skin conditions like atopic dermatitis and psoriasis can be extremely difficult. Current treatments, such as topical corticosteroids, often have limitations and side effects. However, researchers have discovered that the placenta's remarkable properties may provide a breakthrough in effectively addressing these skin conditions. The placenta comprises three essential tissues: decidua, placental membrane, and umbilical cord. Placental derivatives have shown significant potential in treating psoriasis by reducing inflammatory cytokines and inhibiting keratinocyte proliferation. In the case of atopic dermatitis, umbilical cord stem cells have demonstrated anti-inflammatory effects by targeting critical factors and promoting anti-inflammatory cytokines. The scope of benefits associated with placental derivatives transcends these specific applications. They also potentially address other inflammatory skin diseases, such as vitiligo, by stimulating melanin production. Moreover, these derivatives have been leveraged in the treatment of pemphigus and epidermolysis bullosa (EB), showcasing potential as a wound dressing that could eliminate the necessity for painful dressing changes in EB patients. In summary, the integration of placental derivatives stands to revolutionize our approach to inflammatory skin conditions owing to their distinct properties and the prospective benefits they offer. This comprehensive review delves into the current applications of placental derivatives in addressing inflammatory skin diseases, presenting a novel treatment approach.
Stemness of Cancer: A Study of Triple-negative Breast Cancer From a Neuroscience Perspective
Djamgoz MBA
Stemness, giving cancer cells massive plasticity enabling them to survive in dynamic (e.g. hypoxic) environments and become resistant to treatment, especially chemotherapy, is an important property of aggressive tumours. Here, we review some essentials of cancer stemness focusing on triple-negative breast cancer (TNBC), the most aggressive form of all breast cancers. TNBC cells express a range of genes and mechanisms associated with stemness, including the fundamental four "Yamanaka factors". Most of the evidence concerns the transcription factor / oncogene c-Myc and an interesting case is the expression of the neonatal splice variant of voltage-gated sodium channel subtype Nav1.5. On the whole, measures that reduce the stemness make cancer cells less aggressive, reducing their invasive/metastatic potential and increasing/restoring their chemosensitivity. Such measures include gene silencing techniques, epigenetic therapies as well as novel approaches like optogenetics aiming to modulate the plasma membrane voltage. Indeed, simply hyperpolarizing their membrane potential can make stem cells differentiate. Finally, we give an overview of the clinical aspects and exploitation of cancer/TNBC stemness, including diagnostics and therapeutics. In particular, personalised mRNA-based therapies and mechanistically meaningful combinations are promising and the emerging discipline of 'cancer neuroscience' is providing novel insights to both fundamental issues and clinical applications.
Automated Manufacturing Processes and Platforms for Large-scale Production of Clinical-grade Mesenchymal Stem/ Stromal Cells
Strecanska M, Sekelova T, Smolinska V, Kuniakova M and Nicodemou A
Mesenchymal stem/stromal cells (MSCs) hold immense potential for regenerative medicine due to their remarkable regenerative and immunomodulatory properties. However, their therapeutic application requires large-scale production under stringent regulatory standards and Good Manufacturing Practice (GMP) guidelines, presenting significant challenges. This review comprehensively evaluates automated manufacturing processes and platforms for the scalable production of clinical-grade MSCs. Various large-scale culture vessels, including multilayer flasks and bioreactors, are analyzed for their efficacy in MSCs expansion. Furthermore, automated MSCs production platforms, such as Quantum Cell Expansion System, CliniMACS Prodigy, NANT001/ XL, CellQualia™, Cocoon Platform, and Xuri™ Cell Expansion System W25 are reviewed and compared as well. We also underscore the importance of optimizing culture media specifically emphasizing the shift from fetal bovine serum to humanized or serum-free alternatives to meet GMP standards. Moreover, advances in alternative cryopreservation methods and controlled-rate freezing systems, that offer promising improvements in MSCs preservation, are discussed as well. In conclusion, advancing automated manufacturing processes and platforms is essential for realizing the full potential of MSCs-based regenerative medicine and accomplishing the increasing demand for cell-based therapies. Collaborative initiatives involving industry, academia, and regulatory bodies are emphasized to accelerate the translation of MSCs-based therapies into clinical practice.
Therapeutic Properties of M2 Macrophages in Chronic Wounds: An Innovative Area of Biomaterial-Assisted M2 Macrophage Targeted Therapy
Nazari M, Taremi S, Elahi R, Mostanadi P and Esmeilzadeh A
Wound healing is a dynamic, multi-stage process essential for restoring skin integrity. Dysregulated wound healing is often linked to impaired macrophage function, particularly in individuals with chronic underlying conditions. Macrophages, as key regulators of wound healing, exhibit significant phenotypic diversity, ranging from the pro-healing M2 phenotype to the pro-inflammatory M1 phenotype. Imbalances in the M1/M2 ratio or hyperactivation of the M1 phenotype can delay the normal healing. Consequently, strategies aimed at suppressing the M1 phenotype or promoting the shift of local skin macrophages toward the M2 phenotype can potentially treat chronic non-healing wounds. This manuscript provides an overview of macrophages' role in normal and pathological wound-healing processes. It examines various therapeutic approaches targeting M2 macrophages, such as ex vivo-activated macrophage therapy, immunopharmacological strategies, and biomaterial-directed macrophage polarization. However, it also highlights that M2 macrophage therapies and immunopharmacological interventions may have drawbacks, including rapid phenotypic changes, adverse effects on other skin cells, biotoxicity, and concerns related to biocompatibility, stability, and drug degradation. Therefore, there is a need for more targeted macrophage-based therapies that ensure optimal biosafety, allowing for effective reprogramming of dysregulated macrophages and improved therapeutic outcomes. Recent advances in nano-biomaterials have demonstrated promising regenerative potential compared to traditional treatments. This review discusses the progress of biomaterial-assisted macrophage targeting in chronic wound repair and addresses the challenges faced in its clinical application. Additionally, it explores novel design concepts for combinational therapies, such as incorporating regenerative particles like exosomes into dressing materials or encapsulating them in microneedling systems to enhance wound healing rates.
Unlocking the Epigenetic Symphony: Histone Acetylation Orchestration in Bone Remodeling and Diseases
Cai J, Deng Y, Min Z, Li C, Zhao Z, Yi J and Jing D
Histone acetylation orchestrates a complex symphony of gene expression that controls cellular fate and activities, including the intricate processes of bone remodeling. Despite its proven significance, a systematic illustration of this process has been lacking due to its complexity, impeding clinical application. In this review, we delve into the central regulators of histone acetylation, unveiling their multifaceted roles in modulating bone physiology. We explore both contradictory and overlapping roles among these regulators and assess their potential as therapeutic targets for various bone disorders. Furthermore, we highlight current applications and discuss looming questions for a more effective use of epigenetic therapy in bone diseases, aiming to address gaps in knowledge and clinical practice. By providing a panoramic view of histone acetylation's impact on bone health and disease, this review unveils promising avenues for therapeutic intervention and enhances our understanding of skeletal physiology, crucial for improving therapeutical outcomes and quality of patients' life.
Can miRNAs in MSCs-EVs Offer a Potential Treatment for Hypoxic-ischemic Encephalopathy?
Al-Ward H, Chen W, Gao W, Zhang C, Yang X, Xiong Y, Wang X, Agila R, Xu H and Sun YE
Neonatal hypoxic-ischemic encephalopathy (HIE) is a critical condition resulting from impaired oxygen and blood flow to the brain during birth, leading to neuroinflammation, neuronal apoptosis, and long-term neurological deficits. Despite the use of therapeutic hypothermia, current treatments remain inadequate in fully preventing brain damage. Recent advances in mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) offer a novel, cell-free therapeutic approach, as these EVs can cross the blood-brain barrier (BBB) and deliver functional microRNAs (miRNAs) to modulate key pathways involved in inflammation and neuroprotection. This review examines how specific miRNAs encapsulated in MSC-EVs-including miR-21, miR-124, miR-146, and the miR-17-92 cluster-target the complex inflammatory responses that drive HIE pathology. By modulating pathways such as NF-κB, STAT3, and PI3K/Akt, these miRNAs influence neuroinflammatory processes, reduce neuronal apoptosis, and promote tissue repair. The aim is to assess the therapeutic potential of miRNA-loaded MSC-EVs in mitigating inflammation and neuronal damage, thus addressing the limitations of current therapies like therapeutic hypothermia.
HucMSCs-derived Exosomes Promote Lung Development in Premature Birth via Wnt5a/ROCK1 Axis
Li X, Huang L, Mao M, Xu H, Liu C, Liu Y and Liu H
Bronchopulmonary dysplasia (BPD) frequently affects extremely preterm and low birth weight infants, with current treatments lacking specificity. Enhancing extra-uterine preterm alveoli development and repairing damage are crucial for BPD management. Here we show that exosomes derived from human umbilical cord mesenchymal stem cells (hucMSCs-Exos) can enhance fetal lung development in mice by delivering specific contents. Briefly, hucMSCs-Exos were extracted using ultracentrifugation and identified by transmission electron microscopy (TEM), flow cytometry, Western blot (WB), and nanoparticle tracking analysis (NTA). These exosomes were then administered to pregnant mice via tail vein injection. Embryonic lung tissues were collected at E13.5 and E18.5 via cesarean section and analyzed using hematoxylin-eosin (HE) staining, immunofluorescence, and TEM. Proteomic analysis was conducted to identify protein components in the exosomes, and WB was used to assess protein expression changes. hucMSCs-Exos from full-term infants were more effective in promoting cell proliferation than those from preterm infants. In vivo, full-term hucMSCs-Exos significantly enhanced alveolarization in fetal lung tissues. Proteomic analysis revealed higher Wnt5a expression in full-term hucMSCs-Exos, and further experiments confirmed a direct interaction between Wnt5a and ROCK1. WB also showed increased expression of the autophagy marker LC3B in the lung tissues of mice treated with full-term exosomes. In conclusion, term hucMSCs-Exos may directly regulate the phosphorylation of ROCK1 in mouse lung tissue through naturally enriched Wnt5a, thus promoting autophagy of AT2 cells and lamellar body development, and ultimately enhance the alveolarization and reducing the incidence of BPD in premature infants.
Mitochondria's Role in the Maintenance of Cancer Stem Cells in Hepatocellular Carcinoma
Elhinnawi MA, Boushra MI, Hussien DM, Hussein FH and Abdelmawgood IA
Hepatocellular carcinoma (HCC) is the predominant form of liver cancer and is recognized as a major contributor to cancer-related mortality worldwide. Cancer stem cells (CSCs) are a tiny group of cancer cells that possess a significant ability to regenerate themselves, form tumors, and undergo differentiation. CSCs have a pivotal role in the initiation, spread, recurrence, and resistance to treatment of cancer. As a result, they are very susceptible to being targeted for therapeutic intervention. The potential to cure HCC may be achieved by efficiently targeting drugs that eradicate cancer stem cells. Mitochondria have a crucial function in granting drug resistance to cancer stem cells by means of mitochondrial metabolism, biogenesis, and dynamics. Dysfunction in mitochondrial metabolic processes, such as mitochondrial oxidative phosphorylation (OXPHOS), calcium signaling, and reactive oxygen species (ROS) generation, contributes to the initiation and progression of human malignancies, including HCC. ROS have both beneficial and detrimental effects depending on their concentration. Consequently, ROS have become a prominent subject in the study of the fundamental mechanisms of HCC. Furthermore, an imbalance in the process of creating new mitochondria is a characteristic feature of CSCs, and an increase in mitochondrial biogenesis is associated with the heightened resistance observed in CSCs. This article provides a detailed examination of the involvement of mitochondria in the preservation of CSCs, as well as the spread of HCC. A deeper understanding of how mitochondria participate in tumorigenesis and drug resistance could result in the discovery of novel cancer treatments.
Retinal Organoids from Induced Pluripotent Stem Cells of Patients with Inherited Retinal Diseases: A Systematic Review
Lee YJ and Jo DH
Currently, most inherited retinal diseases lack curative interventions, and available treatment modalities are constrained to symptomatic approaches. Retinal organoid technology has emerged as a method for treating inherited retinal diseases, with growing academic interest in recent years. The purpose of this review was to systematically organize the current protocols for generating retinal organoids using induced pluripotent stem cells from patients with inherited retinal disease and to investigate the application of retinal organoids in inherited retinal disease research.
Correction: Current Landscape of iPSC Haplobanks
Escribá R, Beksac M, Bennaceur-Griscelli A, Glover JC, Koskela S, Latsoudis H, Querol S and Alvarez-Palomo B
Patient-Derived Organoids: A Game-Changer in Personalized Cancer Medicine
Abbasian MH, Sobhani N, Sisakht MM, D'Angelo A, Sirico M and Roudi R
Research on cancer therapies has benefited from predictive tools capable of simulating treatment response and other disease characteristics in a personalized manner, in particular three-dimensional cell culture models. Such models include tumor-derived spheroids, multicellular spheroids including organotypic multicellular spheroids, and tumor-derived organoids. Additionally, organoids can be grown from various cancer cell types, such as pluripotent stem cells and induced pluripotent stem cells, progenitor cells, and adult stem cells. Although patient-derived xenografts and genetically engineered mouse models replicate human disease in vivo, organoids are less expensive, less labor intensive, and less time-consuming, all-important aspects in high-throughput settings. Like in vivo models, organoids mimic the three-dimensional structure, cellular heterogeneity, and functions of primary tissues, with the advantage of representing the normal oxygen conditions of patient organs. In this review, we summarize the use of organoids in disease modeling, drug discovery, toxicity testing, and precision oncology. We also summarize the current clinical trials using organoids.
Progress in Transdifferentiation of Autologous Alternative Cell Sources into Corneal Epithelial Cells
Wang B, Zhao JL, Cai WY, Wang GY, Li YZ, Wang JS, Xie HT and Zhang MC
Corneal limbal epithelial stem cells (LESCs) play a crucial role in corneal epithelium regeneration. Severe damage to these cells can result in limbal stem cell deficiency (LSCD), characterized by repeated corneal conjunctivalization, leading to corneal turbidity and scar formation. Restoring functional LESCs and their ecological location are essential for treating LSCD. The goal of this review is to provide researchers and clinicians with key insights into LESCs biology and to conclude the current cell-based therapies advancement in LSCD treatments. Therapeutic cell resources mainly include mesenchymal stem cells (MSCs), embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), skin keratinocyte stem cells (SKCs), and oral mucosal epithelial cells (OMECs).
Adipose-Derived Mesenchymal Stem Cell Secretome Attenuates Prion Protein Peptide (106-126)-Induced Oxidative Stress via Nrf2 Activation
Zayed M and Jeong BH
Pulse Activation of Retinoic Acid Receptor Enhances Hematopoietic Stem Cell Homing by Controlling CXCR4 Membrane Presentation
Geng N, Yu Z, Zeng X, Chen Y, Sheng M, Xu D, Yan M, Yang M and Huang X
The interplay between metabolic signaling and stem cell biology has gained increasing attention, though the underlying molecular mechanisms remain incompletely elucidated. In this study, we identify and characterize the role of adapalene (ADA), a retinoic acid receptor (RAR) agonist, in modulating the migration behavior of hematopoietic stem cells (HSCs). Our initial findings reveal that ADA treatment suppresses hematopoietic stem and progenitor cell (HSPC) mobilization induced by AMD3100 and G-CSF. Furthermore, we demonstrate that ADA treatment upregulates the surface expression of CXCR4 on HSPCs, resulting in enhanced chemotaxis towards CXCL12. Mechanistically, our study suggests that ADA enhances CXCR4 surface presentation without increasing CXCR4 mRNA levels, pointing towards a non-canonical role of RAR signaling in regulating intracellular trafficking of CXCR4. In vivo experiments show that ADA administration significantly enhances HSC homing efficiency. Additionally, competitive transplantation assays indicate a marked increase in donor chimerism following ADA treatment. These findings highlight the critical role of retinoic acid signaling in regulating HSC homing and suggest its potential for advancing novel HSC-based therapeutic strategies.