Search Results (3,630)

Diabetes mellitus is primarily caused by the loss or malfunction of insulin-producing β-cells, and although current therapies improve glycemic control, they do not restore physiologic insulin secretion. Advances in stem cell biology and organoid engineering have led to the development of pancreatic organoids and induced pluripotent stem cell (iPSC)-derived β-cells as promising platforms for disease modeling, drug testing, and regenerative medicine. Pancreatic organoids generated from ductal, acinar, or progenitor populations can recapitulate key anatomical and functional features of native pancreatic tissue, enabling studies of development, injury, and regeneration. In parallel, improvements in iPSC differentiation protocols have produced β-like cells capable of insulin secretion in response to glucose, although achieving full functional maturity remains a challenge. Bioengineering strategies, including biomaterial scaffolds, microfluidic platforms, endothelial co-culture systems, three-dimensional bioprinting, and CRISPR-based genome editing, have enhanced the stability, vascular compatibility, and functional performance of both organoid and iPSC-derived systems. Despite these advances, variability in differentiation efficiency, limited β-cell maturity, and poor long-term survival continue to hinder clinical translation. Together, pancreatic organoids and iPSC-derived β-cells represent complementary platforms that advance fundamental research and support the development of β-cell replacement therapies, with ongoing integration of bioengineering approaches expected to accelerate progress toward reproducible, scalable, and clinically relevant β-cell regeneration. Full article

Trained immunity is a concept that is currently in development and refers to the long-term functional reprogramming of innate immune cells in response to microbial or inflammatory stimuli. This process serves a dual purpose in the gastrointestinal tract, contributing to chronic inflammatory conditions like inflammatory bowel disease and maintaining host defense. The production of pro-inflammatory mediators is augmented by epigenetic and metabolic changes that are induced by the persistent activation of innate immune cells, which is triggered by microbial components and damage-associated signals. Although this increased responsiveness may initially be protective, sustained activation leads to tissue damage, epithelial barrier dysfunction, and chronic inflammation. These mechanisms are significant contributors to colorectal carcinogenesis, particularly in colitis-associated cancer. Through the activation of oncogenic signaling pathways, the establishment of a pro-tumorigenic microenvironment, and an increase in oxidative stress, trained immunity also influences tumor development. Additionally, the systemic reprogramming of hematopoietic progenitor cells has the potential to exacerbate inflammation and facilitate the progression of tumors. The identification of epigenetic and metabolic biomarkers associated with trained immunity can lead to novel diagnostic opportunities. Targeting metabolic and epigenetic pathways, as well as regulating the intestinal microbiota, is a promising therapeutic approach that could enhance the effectiveness of treatments for colorectal cancer while minimizing adverse effects on the immune system. Nevertheless, it is necessary to maintain a delicate equilibrium to suppress pathological inflammation without compromising protective immune responses. In general, trained immunity may represent a potentially relevant mechanistic link between chronic inflammation and colorectal cancer; however, its role remains context-dependent and not yet fully defined. Full article

Immune thrombocytopenia (ITP) is an autoimmune disease. Megakaryocyte dysfunction caused by autoimmune response can lead to thrombocytopenia, and the underlying mechanism is still unclear. Single-cell sequencing analysis revealed the heterogeneity of CD34 + HSPCs in bone marrow between ITP patients and healthy groups. Pre-B cell population 1 (pre-B1) showed a significantly lower percentage contribution in ITP groups, and the underlying mechanism involves cell cycle-, cell apoptosis- and cell death-related pathways. The number of eosinophil–basophil mast cell progenitors (EBMPs) is significantly increased in ITP patients and the DEGs of the EBMPs in ITP patients were significantly enriched in immune-related pathways. Further, immunofluorescent staining and Western blot assay highlight C-X-C Motif Chemokine Ligand 8 (CXCL8) and Interferon Regulatory Factor 1 (IRF1) expression were significantly increased in the EBMPs of ITP patients. Furthermore, cell–cell communication analysis identified an impaired LGALS9-CD44 axis between EBMP cells and MkP1 cells in ITP patients, suggesting that targeting the LGALS9-CD44 interaction might hold promise as a therapeutic approach for ITP. Our observations indicate that ITP patients exhibit an elevated proportion of EBMP cells alongside a reduced proportion of pre-B1 cells. CXCL8 and IRF1 are potentially associated with EBMP cell dysfunction and the ITP disease process. Furthermore, the diminished LGALS9-CD44 axis between EBMP and MkP1 cells may contribute to ITP progression, suggesting a direction for future therapeutic investigation. Full article

Hematopoietic stem and progenitor cells (HSPCs) in the bone marrow are highly vulnerable to radiation-induced damage. Systematic delineation of lineage-specific transcription factor (TF) programs, together with in silico perturbation analyses, provides a valuable approach for identifying regulators capable of accelerating hematopoietic reconstruction after irradiation. Here, using single-cell RNA sequencing (scRNA-seq), we characterized the dynamics of HSPCs at both cellular abundance and transcriptional regulation levels following irradiation and used in silico TF perturbation to predict their effects on lineage commitment. We found that granulocyte–macrophage progenitor (GMP) differentiation is consistently prioritized after irradiation, accompanied by enhanced activity of proliferation-associated drivers. Network-based TF profiling identified Tcf7l2 as a previously unrecognized regulator of early lymphoid differentiation. In silico perturbation further functionally predicted TFs driving differentiation in HSPCs after irradiation, and Hsf1, a factor with pharmacological activation potential, was selected for validation via in vivo celastrol treatment and in vitro knockdown. Collectively, our findings uncover the transcriptional programs governing HSPC lineage biases after radiation exposure and highlight the utility of in silico TF perturbation as a strategy for guiding the therapeutic interventions for radiation-induced hematopoietic injury. Full article

The sigma-1 receptor (S1R) is an endoplasmic reticulum (ER)-resident protein enriched at the mitochondria-associated ER membranes (MAMs) that supports ER homeostasis, preserves mitochondrial function, and enhances cell survival under stress. Disruptions of MAM integrity and prolonged ER stress are well-recognized pathological features of amyotrophic lateral sclerosis (ALS), contributing to motor neuron dysfunction and degeneration. In this study, we evaluated the protective effects of pridopidine, a highly selective and potent S1R agonist currently in clinical development for Huntington’s disease (HD) and ALS, using neural progenitor cells (NPCs) derived from induced pluripotent stem cells (iPSCs) from a patient with sporadic ALS. Exposure of ALS NPCs to the ER stressor tunicamycin increased the ER stress markers binding immunoglobulin protein (BiP) and C/EBP homologous protein (CHOP), disrupted mitochondrial membrane potential, upregulated expression of the mitochondrial apoptotic marker, BAX, increased caspase-3 activation, and reduced cell viability. Pridopidine significantly attenuated tunicamycin-induced BiP and CHOP expression in a biphasic, dose-dependent manner (with maximal efficacy at 1 µM), consistent with the typical pharmacology of S1R agonists. Pridopidine restored mitochondrial membrane potential, reduced mitochondrial apoptotic signaling, shown by decreased BAX expression and caspase-3 activation, and improved survival of ALS-NPCs under ER stress. Co-treatment with the selective S1R antagonist, NE-100, attenuated these effects, supporting an S1R-mediated mechanism of action for pridopidine. Together, these results demonstrate that S1R activation by pridopidine mitigates ER-stress-induced mitochondrial dysfunction and cell loss in ALS-NPCs, resulting in enhanced survival of NPCs supporting the therapeutic potential of pridopidine in ALS. Full article

Fetal hypoxia and maternal stress during pregnancy are major risk factors for neurological disorders. The effects of maternal hypoxia may be transmitted to the next generation through persistent alterations in maternal endocrine and metabolic regulation. In this study, using immunohistochemistry, quantitative RT-PCR, and Western blotting, we assessed morphological features and HIF1-dependent processes in the fetal and adult brains of progeny of female rats exposed to maternal hypoxia (PMH). We identified a delay in progenitor cell differentiation into neurons at embryonic day 14, a decreased number of neurons in the hippocampus, an increased number of astrocytes in the prefrontal cortex, and a decreased number of astrocytes in the raphe nuclei of the PMH rats. However, no significant changes were observed in HIF1α protein levels or in the protein levels of HIF1-dependent gene products in the examined brain structures. Thus, the transgenerational effect of maternal hypoxia is manifested as structural disturbances of brain development but is not accompanied by changes in HIF1-dependent metabolism. Full article

Skin and its appendages form an integrated system of ectodermal mini-organs that rely on Wnt signaling for lifelong homeostasis and regeneration; yet, the pathway operates in a highly organ-specific manner in each compartment. In interfollicular epidermis, the Wnt activity is spatially graded, thus maintaining the balance between basal progenitor proliferation and terminal differentiation. The hair follicle is governed by an intrinsic oscillator based on cross-regulation between Wnt and BMP signaling, providing a cell-autonomous layer of control over hair cycle dynamics. Finally, the nail organ is characterized by the spatial compartmentalization of Wnt activity, with a distal matrix activation zone supported by specialized mesenchymal niche cells that sustain continuous nail plate growth and coordinate the digit tip regeneration. Understanding these divergent regulatory architectures provides a conceptual framework for targeted regenerative strategies aimed at enhancing repair in skin and its appendages. Therefore, in this review, we synthesize recent molecular studies on Wnt signaling in the adult skin, hair follicles, and nail mini-organs, highlighting appendage-specific features that underlie their distinct regenerative capacities. We further discuss how dysregulated Wnt signaling contributes to skin, hair, and nail pathologies such as alopecia, chronic wounds, excessive scarring, skin cancer, and nail deformations, and summarize the emerging strategies that target Wnt pathway to therapeutically enhance hair regrowth, wound repair, cancer treatment, and digit tip regeneration. Full article

Allogeneic hematopoietic cell transplantation (HCT) has been used for decades to treat certain malignant and non-malignant hematological conditions, but challenges remain. Increased understanding of disease mechanisms and recent developments in genome editing have enabled alternative strategies utilizing gene-edited autologous HCT and many of these have progressed to the clinic. We present here a comprehensive review of clinical trials of gene-edited autologous hematopoietic stem cells for the treatment of hemoglobinopathies and immunodeficiencies. Searches of major international clinical trial registries were carried out using specific key words. In total, 44 interventional clinical trials investigating gene-edited autologous stem cell therapies were identified, with CASGEVY (exagamglogene autotemcel) being the only product approved to date. Hemoglobinopathies were the most common indication (n = 37) followed by immunodeficiencies (n = 4), with single trials in HIV-1 infection, pyruvate kinase deficiency and limb–girdle muscular dystrophy. Gene-editing strategies fall into three categories: disruption of the BCL11A erythroid enhancer, editing of the γ-globin promoter and direct correction or disruption of disease-relevant genes. CD34⁺ hematopoietic stem and progenitor cells are the most common cell types edited, and CRISPR-Cas9 is the most widely used gene-editing modality. While results are encouraging, efficient intracellular delivery of gene-editing tools, editing efficiencies and off-target editing remain challenges for the field. Full article

Erythropoiesis is tightly regulated by lineage-specific transcription factors that govern erythroid commitment, proliferation, and differentiation. A core erythroid transcriptional network, together with non-DNA-binding cofactors, occupies regulatory regions of genes essential for erythroid development. This process is further shaped by epigenetic mechanisms, including histone post-translational modifications and long-range chromatin interactions. CCCTC-binding factor (CTCF) is a multifunctional regulator with a central role in three-dimensional chromatin organization. Although CTCF has been implicated in hematopoietic differentiation and leukemogenesis, its specific function in erythropoiesis remains poorly defined. Here, we investigated the role of CTCF during erythroid differentiation using two complementary models: pluripotent K562 leukemia cells and primary human CD34⁺ hematopoietic stem/progenitor cells, each induced toward the erythroid lineage by distinct stimuli. In both systems, CTCF silencing impaired erythroid differentiation by repression of key erythroid transcription factor genes, including LMO2, KLF1, MYB, and ETS1. This repression was associated with enrichment of repressive histone marks at CTCF-binding sites within their regulatory regions. Moreover, CTCF cooperated with cohesin to establish and stabilize long-range chromatin interactions at these loci. These results provide new insight into how CTCF-dependent chromatin regulation contributes to normal erythroid development and suggest that perturbation of this regulatory axis may have implications for hematopoietic disorders and malignancies. Full article

Exosomes (EXs) mediate intercellular communication in the tissue microenvironment. We previously demonstrated that endothelial progenitor cell-derived exosomes (EPC-EXs) from exercised mice protect neurons and cerebral endothelial cells from hypoxia- and hypertension- induced injury ex vivo, suggesting their therapeutic potential in hypertensive ischemic injury. Here, we investigated whether exercise-conditioned EPC-EXs (ET-EPC-EXs) confer protection against acute ischemic injury. Hypertensive transgenic mice were divided into donor and recipient groups. Donor mice underwent treadmill exercise to generate ET-EPC-EXs. Recipient mice was subjected to middle cerebral artery occlusion and received ET-EPC-EXs via tail vein injection (2 × 10⁸/100 μL saline) two hours after stroke onset. Cerebral blood flow (CBF) was assessed, and brains were collected on day two for histological and molecular analyses. Our data showed that ET-EPC-EXs were robustly taken up by cerebral cells, predominantly in the penumbra in the ipsilateral hemisphere. ET-EPC-EXs reduced cell death and microglia activation and restored tight-junction proteins. Moreover, ET-EPC-EX treatment preserved CBF and improved sensorimotor function on day two post-stroke. Mechanistically, ET-EPC-EXs suppressed p38 activation, accompanied by reduced matrix metalloproteinase-3 and cytochrome c levels in the ipsilateral brain. Collectively, these findings demonstrate that EPC-EXs from exercise mice improve sensorimotor functions and confer protection in hypertensive ischemic brain injury, likely through attenuation of neuroinflammation and preservation of vascular integrity via modulation of the p38 signaling. Full article

Acetohydroxy acid synthase (AHAS) are key targets for herbicide resistance breeding in Brassica crops, yet the evolutionary origin and functional role of AHAS2 genes in Brassica napus (AACC) and B. carinata (BBCC) remain poorly understood. Here, we investigated the distribution, ancestry, and agronomic trait associations of AHAS2 across 227 accessions representing six Brassica species. Bra.AHAS2 was amplified in 21 of 42 B. rapa (AA) accessions, and Bol.AHAS2 in 10 of 15 B. oleracea (CC) accessions. In B. napus, BnaA.AHAS2 and BnaC.AHAS2 were amplified in 73/131 and 30/131 accessions, respectively, with 19 accessions showing amplification of both homologs. All seven B. carinata accessions amplified BcaC.AHAS2. No AHAS2 homologs were amplified in three B. nigra (BB) or 29 B. juncea (AABB) accessions. Phylogenetic and gene structure analyses revealed that BnaA.AHAS2 (in B. napus) originated from Bra.AHAS2 of B. rapa, whereas BnaC.AHAS2 (in B. napus) and BcaC.AHAS2 (in B. carinata) derived from Bol.AHAS2 of B. oleracea. Association analysis showed the amplification of BnaA.AHAS2 or BnaC.AHAS2 was not associated with tribenuron-methyl resistance. However, amplification of BnaA.AHAS2 was significantly associated with reduced plant height, branching height, silique number on the terminal raceme, seed yield per plant, and thousand-seed weight in B. napus. Furthermore, haplotypes of BnaA.AHAS2 (BnaA05g03070D) were significantly associated with eicosenoic acid content, oleic acid content, flowering time, and cadmium translocation. Collectively, these findings resolve the diploid progenitor origins of AHAS2 in Brassica allotetraploids and reveal previously unrecognized associations of AHAS2 with agronomic and stress-related traits, offering valuable insights for molecular breeding in oilseed Brassica crops. Full article

The temporomandibular joint (TMJ) relies on specialized progenitor cells for tissue maintenance and repair. We characterized TMJ-derived progenitor cells in mice and investigated the role of Evc2-mediated Hedgehog signaling. Progenitor cells from the anterior TMJ exhibited greater colony-forming capacity and an elongated morphology, while posterior cells were cuboidal, highlighting regional heterogeneity. TMJ-derived progenitors demonstrated multipotency, differentiating into osteogenic and chondrogenic lineages. Gli1-expressing, slow-cycling cells localized to the ligament attachment regions, initially accumulating there and not overlapping with specialized cells (Col1⁺ cells). Conditional Evc2 disruption in Gli1-expressing cells paradoxically augmented expression of Gli1 and mechanosensors (Yap, Wwtr1, Piezo1), and produced more confluent, rapidly expanding colonies. We hypothesize that these colonies are primarily composed of transit amplifying cells (TACs), which may proliferate robustly but face challenges in terminal differentiation. These results reveal critical roles for EVC2 and regional progenitor cell diversity in TMJ regenerative biology and suggest that targeting cell signaling and mechanical factors may inform novel strategies for TMJ disorder therapies. Full article

Animal studies have shown that early life exposure to general anesthetics may impair brain development. However, the implications of this phenomenon in human patients remain unclear. In this study, we use an induced pluripotent stem cell (iPSC)-derived human brain microphysiological system (bMPS) to investigate the effects of early sevoflurane (SEV) exposure on human brain development. Human iPSCs were cultured and differentiated into neural progenitor cells (NPCs) and then into bMPS. At week 8, bMPSs were exposed to 2.4% SEV for 4 h. Four weeks after exposure, immunofluorescence (IF), Western blotting (WB), and quantitative real-time polymerase chain reaction (qPCR) were conducted to evaluate the alteration of nerve cells in bMPS. After SEV exposure, the number of apoptotic cells increases, and the level of neural differentiation markers decreases. The ratios of mature neurons over NPCs and mature oligodendrocytes over oligodendrocyte progenitor cells (OPCs) are reduced, which leads to a reduction in myelination. SEV also impedes the development of astrocytes and synaptogenesis, especially the formation of excitatory synapses. Meanwhile, SEV increases the expression of molecules in the mammalian target of rapamycin (mTOR) signal pathway. In conclusion, early SEV exposure substantially disrupts the development of human brain tissue, and the mTOR signal pathway is likely to be involved in this alteration. Full article

Mammals and reptiles possess a metanephric kidney as the terminal renal organ for homeostasis of solutes and waste products. The development of the metanephric kidney has primarily been studied in mammalian model systems. Little is known about the conservation of metanephric kidney formation in non-mammalian species such as reptiles. Uniquely, reptiles maintain kidney progenitor cell populations throughout life and continually develop new nephrons, the functional unit of the kidney. The red-eared slider turtle, Trachemys scripta elegans, was utilized to investigate the conservation of reptilian metanephric kidney development. The nephron progenitor cell (NPC) marker, Six2, was detected in whole-mount turtle kidneys in a similar pattern to mammals. However, there were differences in progenitor cell niche morphology where turtle NPC populations formed distinct elongated rows instead of the rosette-like morphology found in the mouse. The pattern of NPC populations in the embryonic turtle kidney was maintained in the adult turtle. Whole-genome bisulfite sequencing was performed on cortical tissue containing the NPC populations from adult turtle kidneys and compared to those of adult mice. Significant conservation of gene methylation was detected in adult cortical tissue between the two species, although unique signatures were detected in turtle samples related to DNA repair and β-catenin signaling. This suggests a high level of conservation of metanephric kidney development at the genetic level. Full article

Background: The prevalence of severe aortic stenosis (AS) is increasing, in accordance with a longer life expectancy. Aortic valve calcification is a multifactorial pathological process involving a complex interplay between different types of regenerative cellular and genetic factors. Among these cells, endothelial progenitor cells (EPCs) and their osteoblastic phenotype subpopulation (EPC-OCNs) have been implicated in vascular remodeling and disease progression. Objectives: To assess longitudinal changes in EPC and EPC-OCN levels in patients with severe symptomatic AS undergoing transcatheter aortic valve implantation (TAVI). Methods: In this prospective observational study, 65 patients with severe AS undergoing TAVI were enrolled. Circulating EPC and EPC-OCN levels were quantified by flow cytometry before the procedure, at 4 ± 1 days, and at 90 ± 29 days after TAVI. EPCs were defined by expression of CD133, CD34, and VEGFR-2. Results: Circulating EPC levels remained unchanged throughout the follow-up. In contrast, circulating EPC-OCNs increased significantly over time. Specifically, CD133+/VEGFR-2+/OCN+ cells rose from 2.50% to 6.25%, CD34+/VEGFR-2+/OCN+ from 2.04% to 4.05%, and VEGFR-2+/OCN+ from 1.46% to 3.01% (all p < 0.01). This suggests an osteogenic response to TAVI, while classical endothelial repair mechanisms were not systemically activated. Conclusions: EPC-OCNs increased significantly following TAVI, possibly reflecting ongoing tissue remodeling or calcification processes. In contrast, the stability of classical EPCs levels suggests limited systemic endothelial regeneration. These observations underscore the potential role of EPC-OCNs as markers or modulators of pre- and post-TAVI vascular remodeling. Full article