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421. Impact of EDTA Formulations and Activation Methods on Stem Cell Response, Antimicrobial Activity and Dentine Integrity: An In Vitro Study.

作者: Letycia Accioly Simões Coelho.;Laura Ferreira Almeida.;Ester Alves Ferreira Bordini.;Fernanda Balestrero Cassiano.;Mirela Cesar Barros.;Talita Tartari.;Flaviana Bombarda de Andrade.;Diana Gabriela Soares Dos Passos.;Marco Antonio Hungaro Duarte.
来源: Aust Endod J. 2026年
This study evaluated the effects of 17% trisodium EDTA and 15% disodium EDTA (EDTAd), with or without activation, on SCAP response, antimicrobial activity and dentine chemical alterations. SCAP viability (Live/Dead) and metabolic activity (Alamar Blue) were assessed, along with antibiofilm and intratubular disinfection against Enterococcus faecalis and Streptococcus mutans, after irrigation with EDTA or EDTAd delivered by conventional irrigation (CI), ultrasonic activation (UA) or diode laser activation (LA). Dentine alterations were analysed by Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). EDTA preserved higher SCAP metabolic activity, particularly at early time points (p < 0.05), while cytotoxicity did not differ among groups. Antibiofilm and intratubular antimicrobial effects were similar across irrigants and activation methods (p > 0.05). EDTAd caused greater alterations in the amide III/phosphate ratio (p < 0.05), with increased smear-layer removal and surface irregularities. EDTA showed greater biological compatibility and fewer dentine alterations, whereas EDTAd induced more pronounced structural changes without antimicrobial differences.

422. Engineered Mesenchymal Stem Cells with Endogenous Trehalose Expression Activate the NRF2-HMOX1 Pathway to Enhance Antioxidant Stress and Wound Healing Capacity.

作者: Zhen Wang.;Xin Liu.;Xin Chen.;Jie Jing.;Qiuyang Chen.;Feiyang Zhou.;Zian Chen.;Wei Fang.;Li Wang.;Yuanyuan Wang.;Zian Li.;Qiang Wang.;Jing Gao.;Jing Zhao.;Guangchao Xu.;Rongqing Pang.
来源: Adv Wound Care (New Rochelle). 2026年21621918261438590页
Oxidative stress limits mesenchymal stem cell (MSC) efficacy in tissue repair by reducing retention and survival at injury sites. Endogenous production of trehalose may enhance MSC resilience and promote skin wound healing.

423. Aortic carboxypeptidase-like protein potentiates β1 integrin signaling in mesenchymal progenitors.

作者: Cheyanne L Frosti.;Diana Yeritsyan.;Matthew D Layne.
来源: Life Sci Alliance. 2026年9卷6期
Fibrosis is a pathological process characterized by persistent fibroblast activation and excessive ECM accumulation. Aortic carboxypeptidase-like protein (ACLP), a secreted ECM protein that binds fibrillar collagen, is up-regulated in fibrotic tissues and promotes fibroblast differentiation through canonical TGFβ receptor signaling. We hypothesized that when presented within the collagen matrix, ACLP would engage integrin-dependent mechanical signaling pathways that contribute to fibrogenic activation. Using 10T1/2 mouse mesenchymal progenitor cells, we identify a previously unrecognized mechanism through which collagen-bound ACLP induces fibrogenic activation via β1 integrin-mediated signaling. Collagen-bound ACLP induced rapid cell spreading, increased β1 integrin activation, and promoted focal adhesion maturation. These adhesion events triggered activation of the GTPases RhoA and Rac1, accompanied by enhanced F-actin assembly and nuclear accumulation of myocardin-related transcription factor A, a key regulator of fibrogenic gene expression. Transcriptomic profiling revealed enrichment of focal adhesion, ECM-receptor interaction, and actin cytoskeletal pathways downstream of collagen-bound ACLP, which was conserved in primary adipose-derived stromal cells. Together, these findings establish collagen-bound ACLP as a matrix-derived cue that links ECM composition to integrin-dependent fibrogenic activation.

424. Fusarielins Q-Y: fusarielin polyketides from Fusarium asiaticum QA-6 inhabiting the roots of the cultivated Artemisia argyi and their antibacterial activity against aquatic pathogens.

作者: Xiao-Shan Shi.;Sui-Qun Yang.;Yu-Liang Dong.;Xiao-Ming Li.;Ling-Hong Meng.;Yan-He Li.;Dun-Jia Wang.;Xing-Wang Zhou.;Bin-Gui Wang.
来源: Phytochemistry. 2026年248卷114908页
Artemisia argyi Levl. et Van. var. argyi cv. Qiai is a commercially important medicinal plant specifically cultivated in Qichun County, Hubei Province of Central China. Investigation of the antibacterial functional constituents of the endophytic Fusarium asiaticum QA-6, which is derived from Qiai, resulted in the characterization of nine previously undescribed polyketides fusarielins Q-Y (compounds 1-9) and two known congeners fusarielins M (compound 10) and F (compound 11). Structurally, compounds 1-9 possess a highly functionalized decalin moiety, whereas compounds 1-3 feature shorter polyene side chains compared to other fusarielins. The shortened chain in 2 and 3 likely results from a missed S-adenosyl-l-methionine (SAM)-dependent methylation, with 3 being an oxidation product of 2. Conversely, the truncation in 1 may stem from a missed acetyl-CoA addition. The isolated compounds were assayed for antibacterial activity against aquatic bacterial pathogens, among which, compounds 1, 5, 10, and 11 exhibited activity against specific Gram-negative strains, with compound 1 inhibited Aeromonas hydrophilia (MIC = 2.92 μM) and Vibrio alginolyticus (MIC = 5.84 μM), compound 5 targeted the aquatic pathogen Edwardsiella ictarda (MIC = 2.39 μM), compound 10 acted against E. ictarda, Vibrio harveyi, and V. parahaemolyticus (each with an MIC value of 2.60 μM), and compound 11 inhibited V. alginolyticus (MIC = 4.80 μM). All these antibacterial activities were equivalent to or superior to those of the positive control, chloramphenicol (MICs = 1.55 to 6.19 μM). In the preliminary screening against HeLa cells, none of the isolated compounds exhibited significant cytotoxic activity at the concentration 20 μM.

425. PCSK9 promotes prostate cancer via facilitating intratumoral cholesterol accumulation and enhancing immunosuppressive tumor microenvironment.

作者: Yan Gu.;Fengxiang Wei.;Ying Dong.;Xiaozeng Lin.;Yingying Su.;Geoffrey Wood.;Nabil G Seidah.;Michael Bonert.;Geoff Werstuck.;Tariq Aziz.;Pierre Major.;Damu Tang.
来源: J Adv Res. 2026年
Cholesterol plays critical roles in prostate cancer (PCa) proliferation, immune evasion, and androgen signaling. PCSK9 regulates cholesterol metabolism. Its role in PCa remains unclear.

426. Umbilical cord-derived mesenchymal stem cells restore renal homeostasis in Alport Syndrome: Mechanistic insights and clinical translation.

作者: Li Huang.;Che Zhang.;Zegan Liu.;Meng Kou.;Yongxia Niu.;Sihua Ou.;Xiaoya Zhou.;Boyu Tan.;Xiaoxian Zhang.;Shaoxiang Chen.;Jianlong Wu.;Jinping Wang.;Jun Wu.;HungFat Tse.;Lijie Ren.;Qizhou Lian.
来源: J Adv Res. 2026年
X-linked Alport syndrome (AS) is a progressive hereditary nephropathy caused by mutations in the COL4A5 gene, leading to end-stage renal disease in young adults. Current treatments are palliative with limited efficacy, highlighting a critical unmet medical need.

427. Dose-dependent biphasic effect of environmental UVA on stem cell function through PRPF40A, TGF-β1, NFATc1 signaling.

作者: Qiwen Zheng.;Hien Thi Thanh Ngo.;Trang Thi Minh Nguyen.;Jae-Woo Kim.;Jin-Woo Choi.;Tae-Hoo Yi.
来源: J Photochem Photobiol B. 2026年278卷113435页
Solar ultraviolet A (UVA) radiation makes up nearly 95% of the ultraviolet spectrum at the Earth's surface, forming a major environmental exposure. High-dose UVA is a well-established driver of phototoxicity and tissue degeneration; however, the impact of low-dose UVA on stem-cell homeostasis remains incompletely defined. Here, we investigated whether UVA elicits a dose-dependent biphasic response in human adipose-derived mesenchymal stem cells (AMSCs) and evaluated PRPF40A as a molecular indicator of stemness status. AMSCs were exposed to single or fractionated UVA regimens (0.05-2 J/cm2), followed by assessments of viability, migration, oxidative stress, apoptosis and senescence, stemness programs, multilineage differentiation, and secretome remodeling. In cultured human AMSCs, UVA induced a biphasic dose-response pattern. An ultra-low dose (0.05 J/cm2) enhanced viability and migratory capacity, reduced basal reactive oxygen species, preserved NANOG/SOX2/OCT4 expression, and promoted chondrogenic potential. In contrast, doses of 0.5 J/cm2 or higher, particularly under cumulative exposure, induced oxidative injury, apoptosis, senescence-like changes, reduced stemness, impaired differentiation, and a pro-inflammatory senescence-associated secretory phenotype. Mechanistically, PRPF40A was inversely associated with stemness and showed dose-dependent co-regulation with TGF-β1 and NFAT-related readouts. Cyclosporine A altered PRPF40A- and TGF-β1-associated responses, supporting a provisional regulatory model linking PRPF40A, TGF-β1, and NFAT signaling under UVA stress. In vivo, HR-1 hairless mice showed minimal changes in skin appearance and stemness markers after low-dose UVA, whereas high-dose UVA caused dermal thinning and downregulation of cutaneous stemness markers, without reproducing a definitive biphasic pattern across the tested dose range. Collectively, our findings suggest that human AMSCs may exhibit a narrow in vitro threshold separating adaptive and injurious UVA responses, and identify PRPF40A as a candidate indicator of UVA-driven stemness destabilization.

428. Recent advances in drug repurposing for dentin repair.

作者: Elvin Jaimon.;Mohammad Alenizy.;Michael D Weir.;Tao Ma.;Hockin H K Xu.;Abraham Schneider.
来源: Arch Oral Biol. 2026年187卷106594页
Exposure of a vital dental pulp following deep caries removal, accidental restorative procedures or trauma can severely affect the dentin-pulp complex in adult permanent teeth. To preserve a biologically functional healthy pulp, promote dentin repair, and minimize invasive and costly procedures, direct pulp capping is commonly used in vital pulp therapies. Despite its well-accepted therapeutic value, current pulp capping inorganic hydraulic calcium-silicate cements like mineral trioxide aggregate show limited targeted bioactive effects. Therefore, repurposing clinically approved drugs or investigational small bioactive agents targeting intracellular signaling pathways relevant to reparative dentinogenesis may translate into novel therapeutic approaches for dentin repair. Here, we review studies published over the past decade that explore two agents for potential repurposing in dentin repair: tideglusib, a glycogen synthase kinase‑3 inhibitor, and metformin, a widely used anti‑diabetic biguanide DESIGN: PubMed was used as the single, web-based search engine and database. Only studies using dental pulp stem cells in which the drugs were investigated as single agents were included.

429. Pulmonary neuroendocrine cell-derived exosomes regulate iron homeostasis and oxidative stress in lung neurons.

作者: Abhimanyu Thakur.;Kui Zhang.;Jonathan Chen.;Shuya Mei.;Jace Chen.;Apolline Verdiell.;Emily Jacobs.;Liza Mulder.;Abigail Whitford.;Ashok Iyaswamy.;Ya-Wen Chen.;Anna Cliffe.;Aaron Esser-Kahn.;Bohao Chen.;Qizhou Lian.;Julian Solway.;Shunpeng Xing.;Huanhuan Joyce Chen.
来源: Sci Adv. 2026年12卷15期eady2696页
Nicotine, the principal addictive component of cigarettes, is linked to cognitive decline and neurodegenerative alterations, likely through oxidative stress and impaired iron regulation in neurons. Yet, underlying molecular pathways remain unclear. This study examined the role of pulmonary neuroendocrine cells (PNECs) in smoke-induced neural changes. Using human pluripotent stem cells, we generated induced PNECs (iPNECs) to overcome culture limitations and performed mechanistic analyses. We found that nicotine exposure stimulates iPNECs to secrete exosomes enriched with serotransferrin, an iron-binding glycoprotein. Neurons internalizing these exosomes displayed elevated levels of transferrin receptor 1 (TFR1), divalent metal transporter 1, and duodenal cytochrome b, associated with ferritin accumulation, oxidative stress, and adenosine triphosphate depletion. Inhibition of TFR1 alleviated these effects. Furthermore, nicotine-triggered exosomes increased α-synuclein expression in neurons in a manner consistent with stress- and vulnerability-associated signatures observed in human lungs and nicotine-exposed mice, highlighting PNEC-derived exosomal signaling that may contribute to neuronal dysfunction.

430. A human iPSC model of tauopathies engineered for 4R tau isoform expression endogenously develops late-stage neuronal tau pathology.

作者: Angelika Dannert.;Nathalie Schulz.;Julien Klimmt.;Lea Knez.;Bernhard Groschup.;Carolina Cardoso Gonçalves.;Caterina Carraro.;Martina Schifferer.;Matthias Brendel.;Dominik Paquet.
来源: Sci Transl Med. 2026年18卷844期eadu9845页
Tauopathies, such as Alzheimer's disease and frontotemporal dementia, are common neurodegenerative diseases characterized by misfolding, hyperphosphorylation, and aggregation of tau. Molecular mechanisms underlying tauopathies are still poorly understood, which is in part due to a lack of human models autonomously developing major disease hallmarks. The formation of late-stage disease phenotypes may require adult tau isoform expression, which contributes to tau pathogenesis but is challenging to replicate in human stem cell-derived systems, thus impeding research on underlying mechanisms and drug development. Here, we show that induction of adult human brain-like 4R tau isoform expression enables cell-intrinsic formation of late-stage tauopathy hallmarks in induced pluripotent stem cell-derived neurons engineered to contain synergistic tau mutations without exogenous sources of tau pathology. Neurons accumulated seeding-competent and hyperphosphorylated tau in tangle-like structures. Furthermore, exclusive expression of mutant 4R in the absence of the 3R tau isoform disproportionately intensified pathology, resulting in abundant tau misfolding and aggregation. Last, we provide proof of principle that our model can be translationally applied both to test chemical disease modulators and evaluate human tau PET tracers. Collectively, our model corroborates the central role of 4R tau isoform expression for pathogenesis in human neurons and enables investigations to elucidate mechanisms underlying human tauopathy formation. Moreover, it may serve as a platform supporting urgently needed development of disease-modifying drugs.

431. Corticosteroid resistance is predetermined by early immune response dynamics at acute graft-versus-host disease onset.

作者: Sophie Le Grand.;Yannick Marie.;Delphine Bouteiller.;Margo Fernandez.;Gwendolyn Marguerit.;Marion Lambert.;Émeline Mundwiller.;Émilie Robert.;Régis Peffault de Latour.;Gérard Socié.;Nicolas Vallet.;David Michonneau.
来源: Sci Transl Med. 2026年18卷844期eaeb7834页
Steroid-resistant acute graft-versus-host disease (SR-aGVHD) is the leading life-threatening complication after allogeneic hematopoietic stem cell transplantation. Therapeutic development is impeded by scarce knowledge of biological pathways leading to steroid resistance after aGVHD diagnosis. To gain insight into circulating immune cell subsets and their functions at the onset of aGVHD, we performed a single-cell deep phenotyping and transcriptome analysis on peripheral blood mononuclear cells from two cohorts of patients (discovery cohort, n = 53; and validation cohort, n = 32) with aGVHD before steroid treatment or without aGVHD. Frequencies of circulating immune subsets were not associated with steroid resistance. However, pathway analysis and inferred ligand-receptor interactions revealed major functional divergences between steroid-sensitive aGVHD (SS-aGVHD) and SR-aGVHD, suggesting that steroid resistance is an intrinsic property of immune cells before any treatment. SR-aGVHD was mainly associated with tumor necrosis factor-α (TNF-α) activation. Steroid resistance resulted from a specific cross-talk characterized by inflammasome and caspase-1 activation in monocyte subsets; by TNF-α/TNF receptor, interleukin-1β (IL-1β), IL-18, CCL3, and CCL4 signaling between myeloid and T cells; and by lower involvement of interferon-α and interferon-γ signaling pathways. Immune trajectories in CD8+ T cells demonstrated a direct transition from an early naïve state to a highly activated one. By contrast, SS-aGVHD involved gene signatures across multiple intermediate differentiation stages during cell-to-cell transitions into CD8+ T subsets. These findings provide evidence that steroid resistance is driven by intrinsic mechanisms already present at the onset of the alloimmune response, which may enable previously unknown therapeutic strategies.

432. Peripheral modulation of Pumilio in intestinal stem cells and the corpus allatum affects sleep latency in Drosophila.

作者: Josué A Rodríguez-Cordero.;Marialena Dorta Avilés.;Imilce A Rodriguez-Fernandez.;Alfredo Ghezzi.;José E Lizardi-Ortiz.;José L Agosto-Rivera.
来源: PLoS One. 2026年21卷4期e0337303页
While central circuits governing sleep are well-studied, the contribution of signaling from peripheral tissues remains a critical yet less understood aspect of sleep regulation. The highly conserved RNA-binding protein Pumilio (Pum) is a post-transcriptional regulator expressed in multiple tissues that influence systemic physiology, but its role in modulating basal sleep from peripheral tissues has not been established. Although Pumilio's function in central neurons has been linked to sleep homeostasis following deprivation, whether it regulates sleep through peripheral mechanisms remains unknown. Here, we use conditional genetic tools in the fruit fly Drosophila melanogaster to demonstrate that genetic manipulation of Pumilio targeting the intestinal stem cells (ISCs) and the endocrine corpus allatum (CA) regulates the transition to sleep. Reducing Pumilio function in either the ISCs or the CA independently and significantly accelerates nighttime sleep onset, while overexpression produces the opposite effect. This behavioral change is accompanied by widespread transcriptional alterations in the head, characterized by a robust upregulation of genes involved in cellular stress responses. Our findings reveal a previously unrecognized gut-endocrine-brain signaling axis and identify peripheral post-transcriptional regulation as a key input to the central control of sleep behavior.

433. A scalable embryonic stem cell-based platform for efficient generation of mitochondrial DNA mutant mice.

作者: Weiwei Fan.;Tae Gyu Oh.;Lillian Crossley.;Hunter Robbins.;Mingxiao He.;Yang Dai.;Morgan L Truitt.;Annette R Atkins.;Michael Downes.;Ronald M Evans.
来源: Proc Natl Acad Sci U S A. 2026年123卷15期e2535453123页
Mitochondria are central to energy metabolism and cellular signaling, and mutations in mitochondrial DNA (mtDNA) can disrupt these processes and contribute to human disease. However, progress in defining how mtDNA variation influences adaptation, pathophysiology, and disease susceptibility has been limited by the lack of suitable animal models. Although recent base-editing approaches enable direct mtDNA modification, their low efficiency restricts the generation of diverse models reflecting human mtDNA variation. Here, we develop a scalable embryonic stem (ES) cell-based platform for efficient production of mtDNA mutant mice. Random mutagenesis using an error-prone mtDNA polymerase generates a broad spectrum of mtDNA mutations, which are transferred into ES cells via a multiplexed cybrid fusion strategy coupled with sensitive mutation detection. Optimized ES cell-embryo aggregation enables robust contribution of mtDNA mutant ES cells to host embryos, producing chimeric mice with germline transmission. Using this platform, we generate a library of 155 donor fibroblast lines carrying distinct homoplasmic single-nucleotide mtDNA mutations that produce diverse mitochondrial phenotypes, including impaired oxidative phosphorylation, increased reactive oxygen species, and altered mitochondrial membrane potential. We further generate 34 female C57BL/6 ES cell lines harboring 18 mtDNA mutations across a range of heteroplasmy levels, yielding multiple chimeric mice and achieving germline transmission for one mutation. These data reveal a strong correlation between mitochondrial function and early embryonic development, suggesting a minimal energetic threshold required for normal development. This scalable resource enables systematic investigation of mtDNA variation in physiology, adaptation, disease mechanisms, and therapeutic development.

434. Protocol to evaluate a lineage marking system in the Drosophila testis.

作者: Muhammed Burak Bener.;Stella M DiPippo.;Boris M Slepchenko.;Mayu Inaba.
来源: STAR Protoc. 2026年7卷2期104479页
Accurate interpretation of genetic lineage tracing data is often confounded by the specificity and sensitivity of promoter activity and recombination rates. Thus, reported values may misrepresent targeted event frequency. Here, we present a protocol to validate a genetic tool for marking "dedifferentiation" in Drosophila testes. We describe steps for long-term live imaging to observe reporter activation and detail procedures to estimate false-positive and false-negative rates by integrating these datasets into a mathematical model. This approach enables rigorous evaluation of system performance. For complete details on the use and execution of this protocol, please refer to Bener et al.1.

435. Polycomb repressive complex 2 insufficiency underlies myeloid leukemia in Down syndrome.

作者: Yutaro Suzuki.;Yaeko Nakajima-Takagi.;Motohiko Oshima.;Yotaro Ochi.;Akiho Tsuchiya.;Shuhei Koide.;Takako Yokomizo-Nakano.;Shuhei Kurosawa.;Ola Rizq.;Ayana Kon.;Satoru Miyano.;Bahityar Rahmutulla.;Atsushi Kaneda.;Manabu Nakayama.;Haruhiko Koseki.;Eugene Yu.;Tsutomu Toki.;Etsuro Ito.;Seishi Ogawa.;Atsushi Iwama.
来源: Blood. 2026年
Children with Down syndrome (DS) have an elevated risk of developing myeloid leukemia in DS (ML-DS). In addition to mutations in GATA1, which generate the truncated isoform GATA1-short (GATA1s), ML-DS requires additional somatic gene mutations, most frequently in cohesion and polycomb repressive complex 2 (PRC2) genes. Here, we show that PRC2 insufficiency underlies ML-DS pathogenesis. Transplantation of Gata1s fetal liver cells followed by deletion of the cohesion subunit Stag2 and/or the PRC2 component Ezh2 induced megakaryocyte-biased differentiation and expansion of megakaryocytic progenitors, culminating in lethal myelofibrosis. Mechanistically, loss of Stag2 or Ezh2 reinforced Gata1s-driven reduced chromatin accessibility at erythroid transcription factor target loci in pre-megakaryocyte/erythroid progenitors (pre-MegEs), thereby promoting megakaryocytic skewing. Ezh2 loss attenuated the Gata1s-mediated global elevation of H3K27me3 in pre-MegEs, resulting in derepression of a broad set of PRC2 target genes and establishing a functionally PRC2-insufficient state. Similarly, Stag2 loss induced a moderate but significant degree of PRC2-insufficient state in Gata1s progenitors. Furthermore, chromosome 21-encoded miR-125b blocked megakaryocytic differentiation of Gata1s progenitors lacking either Stag2 or Ezh2 alone, but drove full transformation and expansion of CD150+Sca-1+c-Kit+ leukemic stem cell-like populations only upon concurrent loss of both Stag2 and Ezh2, leading to acute megakaryoblastic leukemia in mice. These findings reveal that cohesin and PRC2 insufficiencies converge on PRC2 dysfunction while exerting distinct epigenetic effects, and synergize with trisomy 21 and GATA1s to remodel the epigenetic landscape, driving progression from a preleukemic state to overt leukemia.

436. [Allogeneic hematopoietic stem cell transplantation in children's acute myeloblastic leukemia: Survival and relapse].

作者: Nour Ben Abdeljelil.;Insaf Ben Yaiche.;Rihab Ouerghi.;Ines Turki.;Lamia Torjemane.;Dorra Belloumi.;Sabrine Mekni.;Rimel Kanoun.;Anna Chaabane.;Saloua Ladeb.;Tarek Ben Othman.
来源: Tunis Med. 2025年103卷11期1678-1686页
Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is indicated for children with high-risk (HR) acute myeloid leukemia (AML).

437. Cytokinetic abscission failures in a polarized epithelium affect apical membrane size and cilia.

作者: Kaela S Lettieri.;Katrina C McNeely.;Noelle D Dwyer.
来源: Mol Biol Cell. 2026年mbcE25090444页
Cytokinetic abscission genes are linked to cancers and developmental disorders, but the consequences of disrupted abscission in vivo remain under-explored. Previously we showed that in the forebrain of Cep55 knockout (KO) mouse embryos, a subset of neuroepithelial stem cells (NSCs) fail abscission and become binucleate, and some of those undergo p53-mediated apoptosis. Here we use the Cep55 KO to investigate how stochastic abscission failures in a polarized epithelium affect the epithelial architecture. We find that NSCs in Cep55 KO neuroepithelium have preserved epithelial polarity and integrity. However, they have enlarged apical membranes (called apical endfeet), longer primary cilia, and increased biciliation. We then test whether the enlarged apical endfeet arise from filling the space of apoptotic neighbors. Remarkably, blocking apoptosis does not rescue but exacerbates the phenotypes: extra-large apical endfeet have further increased multiciliation, supernumerary centrosomes, and abnormal or multiple nuclei, although epithelial polarity is maintained. These findings elucidate the importance of proper abscission in maintaining polarized epithelial structure, and reveal that p53-mediated apoptosis is a crucial guardian of tissue architecture when cell division defects arise during development and disease.

438. Rapid Analysis of NAD and Other Phosphorylated Metabolites in Complex Biological Samples by Hydrophilic Interaction Liquid Chromatography Coupled with Tandem Mass Spectrometry.

作者: Adela Pravdova.;Maximilian Kleinert.;John Henderson.;Eleni Kafkia.;David Pladevall-Morera.;Caio Y Yonamine.;Jonas T Treebak.;Tetiana Brodiazhenko.;Ilya Terenin.;Jan Jakub Zylicz.;Thomas Moritz.;Ondrej Hodek.
来源: Anal Chem. 2026年
Nucleotides and coenzymes play critical roles in energy metabolism and cellular signaling and as building blocks of nucleic acids. This work addresses the challenges in the measurement of the phosphorylated metabolites using hydrophilic interaction liquid chromatography coupled with mass spectrometry, which facilitates the separation and detection of polar metabolites. Here, we present optimized HILIC-MS/MS methods for rapid analysis of polar metabolites including nucleotides and their derivatives in complex biological matrices, such as murine adipose, skeletal, and liver tissues, human plasma, and bacteria. The developed methodologies enable separation of key nucleotides and other phosphorylated metabolites within 6 min and cofactors such as NAD+, NADH, NADP+, and NADPH within 4 min. Validation of these methods demonstrated high accuracy, precision, and sensitivity and stresses the substantial impact of matrix effects. The applicability of the methods was also tested on 13C-labeling experiments with mouse pluripotent stem cells. Additionally, sample pretreatment techniques, such as liquid-liquid extraction and solid-phase extraction, were evaluated as a tool to decrease the negative impact of matrix effects in complex samples. This work enhances the analytical capabilities for nucleotide quantification in metabolomics, facilitating the study of metabolic pathways and disease markers.

439. Human Amniotic Fluid Stem Cell-mediated Biomechanical Restoration of Urinary Continence in Rats.

作者: Shing-Hwa Lu.;Shiaw-Min Hwang.;Navneet Kumar Dubey.;Ming-Song Tsai.;Tien-Fu Yun.;Jiunn-Wang Liao.
来源: Tissue Eng Regen Med. 2026年
Stress urinary incontinence (SUI) adversely impacts millions worldwide due to weakened pelvic floor muscles and urethral sphincter dysfunction. To date, there is a lack of effective non-surgical treatment for SUI, and no clear consensus has been reached on the optimal stem cell source under regenerative therapy. Existing studies have shown no precise molecular mechanisms underlying stem cell-mediated external urethral sphincter (EUS) regeneration. Therefore, we investigated the regenerative and reparative potential of our clinical-grade human amniotic fluid stem cells (hAFSCs) for treating SUI.

440. Hepatitis C virus core promotes hepatic cancer stem cell formation via β-catenin-mediated EpCAM upregulation.

作者: Jing Yuan.;Jian He.;Wei Liu.;Yang Luo.;Yanping Li.;Xianxi Zheng.;Deming Deng.;Fengliang Tian.;Dan Nie.
来源: Microbiol Spectr. 2026年e0285925页
Hepatitis C virus (HCV) infection is a major cause of hepatocellular carcinoma (HCC). However, how HCV promotes hepatic progenitor cell (HPC) differentiation into hepatic cancer stem cells (HCSCs) remains unclear, particularly the role of β-catenin signaling and epithelial cell adhesion molecule (EpCAM) regulation in this process. We used mouse HPCs (HP14.5 and HP14.5-Core) and human HCC cell lines (Huh7, HepG2) to investigate HCV core function. Cells were transduced with AdCore, AdGFP, or shRNAs targeting EpCAM or β-catenin. Functional properties were evaluated using spheroid formation, ICG uptake, colony formation, migration, invasion, and in vivo tumorigenesis assays. EpCAM promoter activity and Wnt/β-catenin signaling were examined by luciferase reporter assays. Protein expression was measured by RT-PCR and Western blotting, while immunofluorescence and co-immunoprecipitation were used to analyze HCV core-β-catenin interactions. HCV core expression increased spheroid number, reduced ICG uptake, and accelerated tumor growth in xenograft and orthotopic mouse models, consistent with HPC differentiation toward HCSCs. EpCAM, CD133, CD44, and CD90 were strongly upregulated, whereas EpCAM silencing suppressed proliferation, migration, and invasion. Reporter assays revealed that HCV core enhanced EpCAM promoter activity and activated Wnt/β-catenin signaling. Immunofluorescence demonstrated β-catenin nuclear translocation, and co-immunoprecipitation confirmed direct interaction between HCV core and β-catenin. Knockdown of β-catenin reduced EpCAM, c-Myc, and cyclin D1 expression, diminished spheroid formation, restored ICG uptake, and significantly impaired tumorigenesis in vivo. The HCV core-β-catenin-EpCAM axis drives the conversion of HPCs into HCSCs. This pathway is a central mechanism in HCV-related HCC.IMPORTANCEHCV core protein directly interacts with β-catenin, driving its nuclear translocation and activating EpCAM expression. This promotes HPC differentiation into HCSCs, marked by increased spheroid formation, migration, invasion, and tumorigenesis. Silencing EpCAM or β-catenin reverses these effects, confirming that the HCV core-β-catenin-EpCAM axis is a key pathway in HCV-related HCC.
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