Mesenchymal stem cells (MSCs) hold great promise for the treatment of Sjögren disease (SjD) owing to their potent immunomodulatory capacity. However, the precise molecular mechanism by which MSCs regulate the characteristic B cell dysregulation in SjD remains largely unknown. In this study, we found that Pik3cb expression was significantly upregulated in submandibular glands (SMGs) of NOD mice, a well-established SjD model. Notably, genome-wide microarray profiling identified Pik3cb as a pivotal mediator of the therapeutic efficacy of allogeneic MSCs in NOD mice, suggesting it plays a role in SjD pathogenesis and treatment. Systematic investigation of the role of Pik3cb in MSC therapy and B cell regulation revealed that MSC administration and pharmacological inhibition of Pik3cb (using TGX-221) significantly attenuated SjD progression. This attenuation was characterised by the robust suppression of B cell responses, including activation, chemotaxis, plasma cell differentiation, and antibody production. Both interventions effectively restored salivary secretion and alleviated lymphocytic infiltration and fibrosis in the SMGs. Concurrently, a significant shift in the cytokine profile was observed, with diminished pro-inflammatory cytokines (IL-4, IL-6, IFN-γ) and upregulated anti-inflammatory factors (IL-10, TGF-β1) in the SMGs and spleens. Additionally, Pik3cb overexpression in B cells abrogated the MSC-induced therapeutic benefits, confirming the specificity of Pik3cb as a target. Finally, mechanistic studies revealed that MSC efficacy was correlated with Pik3cb suppression, resulting in the subsequent downregulation of Akt/mTOR signalling. In conclusion, this study provides mechanistic evidence that MSC therapy mitigates B cell dysfunction in SjD through the Pik3cb/Akt/mTOR pathway. Furthermore, our data identified Pik3cb as a hitherto unrecognized molecular target in SjD pathogenesis, suggesting that its pharmacological inhibition may represent a promising complementary therapeutic avenue for SjD meriting further investigation.

The decreased reconstruction potential of aging bone marrow mesenchymal stem cells (BMMSCs) fails to resist compromised bone healing, and strategies to remodel the regeneration capacity of senescent BMMSCs are urgently needed. A depletion of ARG1+ macrophages in aging murine exacerbates the impaired reconstructive functionality of BMMSCs, eventually becomes a critical obstacle for aged osteointegration. Herein, we fabricated a niche-like multiscale porous Titanium (p-Ti) implant using a vapor-phase-assisted alloying-dealloying strategy for in-situ manipulating the regenerative repair potential of BMMSCs while alleviating immunosenescence during bone reconstruction. This versatile method can be used to fabricate a porous surface layer on commercial implants with complex geometries. As benchmarked with commercial Ti, the in vitro and in vivo results of rabbits and rats show our niche-like p-Ti efficiently promotes BMMSCs to engender an osteogenic phenotype and attune the areas of bone defect. Moreover, niche-like multiscale porous structure yields rejuvenated ARG1+ macrophages in tandem with BMMSCs osteogenic differentiation at the bone-implant interface, modulating the immunosenescence, and synergistically promoting the osteointegration. Our findings establish that the macrophage can be re-engineered to be youthful for maintaining immune homeostasis, thereby providing a reversible treatment strategy for bone reconstruction of old people with broad applications in other senescence-related diseases.

Bone defect represents one of the most prevalent clinical conditions in orthopedics diseases, and the key to successful therapeutic outcomes lies in achieving early vascularization coupled with late-phase osteogenic differentiation. Growth factor delivery is among the most widely adopted strategies for bone tissue regeneration. However, achieving the spatiotemporal coupled regulation of vascularized bone regeneration remains a major challenge. Proprotein convertase subtilisin/kexin type 9 (PCSK9) exerts a pivotal role in bone metabolism. Our preliminary findings demonstrated that PCSK9 expression is upregulated during bone regeneration, while the supplementation of exogenous PCSK9 can enhance the osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSC). Based on these findings, we fabricated a composite hydrogel by adsorbing PCSK9 onto vascular-derived extracellular matrix (ECM) and incorporating vascular endothelial growth factor (VEGF) into gelatin methacryloyl (GelMA). Taking advantage of the distinct sustained-release profiles of these biomaterials, this hydrogel system was engineered to recapitulate the natural bone defect healing process, thereby enabling the coupled regulation of accelerated early vascularization and enhanced late-phase osteogenic differentiation. Both in vitro and in vivo experimental results confirmed that the constructed composite hydrogel can further potentiate the therapeutic efficacy of PCSK9 and achieve efficient vascularized bone regeneration. Mechanistically, our findings revealed that PCSK9 promotes the osteogenic differentiation of BMMSC via activation of the ERK signaling pathway. Collectively, the PCSK9- and VEGF-loaded composite hydrogel exhibits promising pro-angiogenic and pro-osteogenic coupling capabilities for bone regeneration, which provides novel therapeutic targets and innovative strategies for the clinical management of bone defects.

Conductive nerve scaffolds have emerged as a promising alternative to autologous grafts for promoting nerve regeneration. However, the optimization of scaffold materials and the elucidation of their regulatory mechanisms on neural stem cell (NSC) differentiation remain critical research priorities. Graphdiyne (GDY), a novel two-dimensional carbon allotrope, exhibits excellent electrical conductivity and favorable biocompatibility, yet its application in the neural field is still in its infancy. In this study, a structurally synergistic GDY/polycaprolactone (GDY/PCL) conductive composite scaffold-termed the GDY-Ivy Fiber Neural Scaffold-was fabricated using a combined electrospinning-freeze-drying strategy. This approach enabled efficient GDY loading while preserving its intrinsic properties. The resulting scaffold demonstrated superior electrical conductivity, mechanical strength, structural stability, and cytocompatibility. In vitro experiments further confirmed that the GDY-Ivy Fiber Scaffold significantly promoted NSC differentiation into neurons, inhibited glial activation, and enhanced synapse formation and the generation of functionally mature neurons. RNA-Seq analysis revealed that the scaffold orchestrated multiple key signaling pathways, including neurotrophic factor and Wnt-related pathways, thereby promoting NSC neuronal differentiation and functional maturation. In vivo experiments demonstrated that the GDY-Ivy Fiber Neural Scaffold enhances guidance for axonal oriented growth and Schwann cell activation, and promotes neovascularization, thereby improving the repair quality of peripheral nerve injury. Overall, the GDY-Ivy Fiber Neural Scaffold developed in this study establishes an optimized electrophysiological and structural microenvironment that promotes neuronal growth. These findings not only expand the application scope of carbon-based materials in neuroregenerative medicine but also offer novel design strategies for neural repair scaffolds.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a life-threatening monogenic inborn error of immunity caused by pathogenic variants in the FOXP3 gene. In this report, we describe the clinical and immunologic consequences of a novel FOXP3 variant in an infant with refractory IPEX syndrome. Rapid whole-genome sequencing revealed a missense variant c.1050C>G (p.Ile350Met) in the forkhead domain of FOXP3. FOXP3 expression was abrogated in the regulatory T cell (Treg) subset but was maintained at low levels in activated effector T cells. The frequency of Treg-specific demethylated region (TSDR)-demethylated T cells was within normal range at birth, but it increased to pathologically high levels at 2 wk of age, prior to manifestation of disease symptoms. These results support the clinical relevance of the TSDR-demethylated cell percentage in evaluation of disease activity in IPEX. This case highlights a severe form of IPEX syndrome refractory to multiple immunosuppressive agents and the importance of early immunological studies to verify the clinical significance of novel genetic findings.

Extracellular signal-regulated kinase 5 (ERK5), a unique member of the mitogen-activated protein kinase (MAPK) family, plays a critical role in cell fate determination due to its distinct structure. This review aims to systematically summarize the central role of the ERK5 signaling pathway in cell specification and differentiation. Substantial evidence indicates that, by integrating diverse extracellular signals and regulating key transcription factors, ERK5 precisely controls the fate specification and differentiation of various cell types, including stem cells, neural cells, immune cells, endothelial cells, and osteoblasts. Furthermore, aberrant MEK5/ERK5 signaling is closely linked to the pathogenesis and progression of various diseases, particularly cancer, and is associated with drug resistance. By delineating the signaling mechanisms and functions of ERK5 across different cellular contexts, this review seeks to deepen the understanding of its physiological and pathological activities and to provide new potential targets and insights for regenerative medicine and cancer therapy.

Endometrial receptivity (ER) is a pivotal determinant of successful embryo implantation, and its dysfunction is a major cause of infertility and recurrent implantation failure. Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic strategy due to their multipotency, self-renewal capacity, and potent paracrine activity. This review elucidates the multifaceted mechanisms through which MSCs enhance ER, including direct differentiation into endometrial cells, promotion of angiogenesis via secretion of factors like VEGF, immunomodulation by inducing Treg cells and M2 macrophages, and remodeling of the extracellular matrix. Crucially, we highlight emerging clinical evidence; for instance, in a recent clinical trial, intrauterine infusion of umbilical cord-derived MSCs in women with intrauterine adhesions significantly increased endometrial thickness from a mean of 4.2 ± 0.5 mm to 6.8 ± 0.7 mm and improved the clinical pregnancy rate to 38.5%. Furthermore, we discuss ongoing clinical trials and future directions, such as the development of engineered MSC-derived exosomes and biomaterial-scaffold combinations. Despite challenges in standardization and long-term safety, MSC-based therapy represents a novel and potent approach for regenerating dysfunctional endometrium, offering new hope for refractory infertility.

Trauma-induced heterotopic ossification (THO) is a complication characterized by ectopic lamellar bone formation in soft tissues after trauma. Current treatments are limited by low efficiency, recurrence, and potential impairment of bone healing, highlighting the need for new strategies. Mesenchymal stem cell (MSC) recruitment and osteogenic differentiation are critical in THO pathogenesis. Poly [ADP-ribose] polymerase 1 (PARP1) is involved in regulating osteogenic differentiation, and PJ34, a PARP1 inhibitor, may have potential in THO prevention.

Mesenchymal stem cell (MSC)-derived microvesicles play a pivotal role in the regenerative cascade of wound healing. This study aimed to comparatively evaluate the therapeutic potential of microvesicles isolated from different MSC sources in the healing of diabetic cutaneous wounds.

TAR DNA-binding protein 43 (TDP-43) is a DNA- and RNA-binding protein that regulates gene expression by modulating transcription and RNA processing. It plays pivotal roles in neuronal development and function, and its mislocalization and aggregation are major pathological features of several neurodegenerative diseases. However, the regulatory mechanisms that control Tdp-43 expression and activity during the transition from embryonic stem cells (ESCs) to neural progenitor cells (NPCs) remain poorly understood. Through integrative epigenomic and transcriptomic analyses, we identified multiple intergenic and intragenic enhancers within and around the Tdp-43 locus that generate enhancer RNAs (eRNAs). These eRNAs exhibit dynamic, region-specific expression changes and modulate Tdp-43 transcription in a stage- and context-dependent manner. Specifically, a subset of eRNAs was highly expressed in ESCs and downregulated upon differentiation, while others were selectively retained or induced in NPCs, paralleling changes in enhancer usage and histone modification states. Targeted knockdown of these eRNAs decreased Tdp-43 expression and was accompanied by changes in the expression of pluripotency- and lineage-associated markers, without implying direct control over full differentiation trajectories. These findings uncover a previously unrecognized aspect of Tdp-43 transcriptional regulation and highlight the significance of enhancer dynamics in the epigenetic regulation of TDP-43 expression during early lineage specification.

During vertebrate embryogenesis, hematopoietic stem cells (HSCs) are believed to almost exclusively arise from hemogenic endothelial cells (ECs) of the dorsal aorta through endothelial-to-hematopoietic transition (EHT). It remains elusive whether HSCs can be generated by other tissues. Sclerotomal cells (SCs) in embryonic somites predominantly form vertebrae and ribs, and some SCs may also insert into aortic endothelia. Here we show that a subset of SCs directly enter the vascular lumen to become hematopoietic stem and progenitor cells (HSPCs) in an EHT-independent way in both zebrafish and mouse embryos. The sclerotome-derived HSPCs (scHSPCs) contribute to various blood cells throughout the lifetime. The proportion of scHSPCs increases dramatically when endothelium hematopoiesis is defective. Thus, the sclerotomal hematopoiesis is evolutionarily conserved and would ensure the robustness of hematopoiesis.

Long QT syndrome is clinically associated with recurrent ventricular tachycardia and sudden cardiac death. Mutations in KCNH2, which encodes the pore-forming potassium channel subunit human ether-a-go-go-related gene (Kv11.1), are associated with long QT syndrome type 2 (LQTS2).

Glioblastoma (GBM) is an aggressive brain cancer infiltrated by immunosuppressive myeloid-derived suppressor cells (MDSCs) and confers poor prognosis. To address this, our group developed an adoptive cellular therapy platform specifically for primary central nervous system (CNS) malignancies that yielded significant survival benefits against multiple brain cancer models. Preclinically, this platform establishes proof-of-concept for lymphodepletion achieved through host conditioning with total body irradiation (TBI). While host conditioning is thought to remove immunosuppressive elements, the aim of this study was to determine how immune recovery is affected by adoptive cellular therapy.

There is an urgent need for novel targeted therapeutic strategies for pediatric-type diffuse high-grade glioma (PDHGG) to improve patient outcomes, the development of which demands model systems that accurately recapitulate the specific PDHGG subtypes. Characterization, longitudinal monitoring and, ultimately, evaluation of treatment response in these models requires sensitive non-invasive imaging techniques such as magnetic resonance imaging (MRI).

Scalable manufacturing of human induced pluripotent stem cells (iPSCs) is essential for industrial-scale production of cell therapies and regenerative medicines. However, the 3D aggregate cultures used in manufacturing exhibit substantial spatial and metabolic heterogeneity compared with the relatively homogeneous monolayer systems used in laboratory studies, complicating mechanistic understanding and predictive metabolic modeling across culture scales. To address this challenge, we developed a modular multiscale mechanistic foundation model that links molecular, cellular, and macroscopic processes while accounting for spatial and metabolic heterogeneity. The framework integrates extracellular culture dynamics, intracellular metabolic fluxes, and cellular redox states by extending a previously established monolayer kinetic network and coupling it with a biological systems-of-systems (Bio-SoS) multiscale model for aggregate cultures, incorporating explicit redox interactions. Systematic monolayer and aggregate experiments-including multiple isotopic tracers, extracellular metabolite profiling, and two-photon optical redox imaging-were used to improve and validate the model. This integrated framework unifies heterogeneous datasets across culture configurations and enables mechanistic interpretation of metabolic and redox responses across heterogeneous culture scales, providing a quantitative foundation for scalable iPSC biomanufacturing.

Chemotherapy-induced oral mucositis (CIOM) is a debilitating complication with limited therapeutic options. Mesenchymal stem cells (MSCs) promote tissue repair through paracrine signaling, and stem cell-derived nanovesicles (SC-NVs) have emerged as a scalable, cell-free therapeutic alternative. However, the regenerative potential of SC-NVs has not been investigated in the context of CIOM. This study evaluated the regenerative effects of SC-NVs derived from human adipose-derived MSCs (AD MSCs) in vitro assays and a rat CIOM model. Transcriptomic profiling showed enrichment of wound healing and angiogenesis-related genes in AD MSCs. SC-NVs were produced by serial extrusion and characterized by nanoscale size and reproducible protein content. Following intralesional injection, SC-NVs localized to the ulcer bed and remained detectable for up to 5 days. SC-NV treatment enhanced epithelial regeneration, promoted angiogenesis, and reduced inflammatory markers in vitro and in vivo. These findings support SC-NVs as a scalable, cell-free therapeutic platform for CIOM.

Neural stem cells (NSCs) maintain central nervous system (CNS) homeostasis through self-renewal and differentiation into neurons and glia. Although physical crowding shapes the NSC niche during CNS development, its role in fate determination remains poorly understood. We investigated how NSC crowding influences intercellular junctions and lineage specification in 2D and 3D environments. While crowding promotes neuronal differentiation in both environments, robust junctional remodeling occurred only in 3D. Specifically, 3D crowding uniquely upregulated connexin 43 (Cx43)-mediated gap-junction assembly. Pharmacological Cx43 inhibition selectively attenuated 3D crowding-induced neuronal differentiation, demonstrating that gap-junction signaling is essential for fate determination in 3D. These findings highlight that the regulatory influence of NSC crowding is dimension-dependent and mediated through Cx43 gap-junction communication. By elucidating how biophysical context integrates with intercellular signaling to guide NSC behavior, this study offers mechanistic insights into stem cell biology and informs biomimetic 3D culture systems and regenerative strategies for neural tissue repair.

Postoperative recurrence and metastasis in esophageal squamous cell carcinoma (ESCC) are closely associated with cancer stem cells (CSCs), though the heterogeneity and key molecular mechanisms underlying CSC-driven progression remain incompletely understood. In this study, we identified a malignant, stem-like subpopulation in ESCC using single-cell sequencing data and screened for subpopulation-specific markers via machine learning algorithms, identifying KRT15 as a candidate. Functional experiments in vitro and in vivo demonstrated that the overexpression of KRT15 promoted proliferation, migration, invasion, and stemness in ESCC cells, while its knockdown suppressed these phenotypes. Clinically, high KRT15 expression was significantly associated with poorer overall survival and progression-free survival and served as an independent prognostic risk factor. Collectively, our findings indicate that KRT15 acts as a functional regulator of stemness and invasiveness in ESCC, highlighting its potential as a therapeutic target and a prognostic biomarker for postoperative risk stratification.

Radiation enteritis (RE) is a common complication following radiotherapy, adversely affecting patient prognosis and quality of life. This study aims to analyze the evolving research landscape of RE prevention and management through a data-driven approach, aiming to delineate the developmental trajectory, identify research hotspots and emerging frontiers, and forecast future trends in RE prevention and management.