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Introduction: Pathogenic variants in the OFD1 gene are linked to a spectrum of syndromes that exhibit partial clinical overlap. Hemizygous loss-of-function variants are considered lethal in males,while heterozygous loss-of-function variants generally result in oro-facial-digital syndrome type 1. A reported phenotype,Simpson–Golabi–Behmel syndrome type 2,was published once but remains controversial,with many specialists questioning its validity and arguing about its continued listing in the OMIM database. Methods: To investigate the genetic and phenotypic characteristics of the patients,we performed clinical exome sequencing,family-based genetic analysis,X-inactivation studies,electron microscopy,and detailed clinical assessments. Results: Three patients from unrelated families carrying loss-of-function variants in the OFD1 gene were identified,emphasizing the diverse phenotypic spectrum of OFD1 -associated disorders. The first patient,a female with a heterozygous frameshift variant p.(Gln398LeufsTer2),was diagnosed with oro-facial-digital syndrome type 1. The second patient,a male with a heterozygous nonsense variant p.(Gln892Ter),presented with features resembling Simpson–Golabi–Behmel syndrome type 2,as previously reported under this diagnosis. The third patient,a male with another heterozygous nonsense variant p.(Glu879Ter),exhibited isolated primary ciliary dyskinesia without any syndromic features. Conclusions: This study contributes to the growing body of evidence on the expanding phenotypic spectrum of OFD1 -associated disorders. It underscores the need for further investigation into the molecular mechanisms underlying the diverse presentations and the necessity of re-evaluating diagnostic classifications for conditions such as SGBS2 in the context of variants in the OFD1 gene. View Publication

Borrelia (or Borreliella ) burgdorferi,the causative agent of Lyme disease,is a motile and invasive zoonotic pathogen adept at navigating between its arthropod vector and mammalian host. While motility and chemotaxis are well known to be essential for its enzootic cycle,the role of each methyl-accepting chemotaxis proteins (MCPs) in the infectious cycle of B . burgdorferi remains unclear. In this study,we show that mcp5,a gene encoding one of the most abundant MCPs in B . burgdorferi,is differentially expressed in response to environmental signals and at distinct stages of the pathogen’s enzootic cycle. Notably,mcp5 expression is regulated by the Hk1-Rrp1 and Rrp2-RpoN-RpoS pathways,two key regulatory pathways that are critical for the spirochete’s colonization of the tick vector and mammalian host,respectively. Infection experiments with an mcp5 mutant revealed that spirochetes lacking MCP5 were unable to establish infections in either C3H/HeN mice or Severe Combined Immunodeficiency (SCID) mice,which are deficient in adaptive immunity,underscoring MCP5’s critical role in mammalian infection. However,the mcp5 mutant was able to establish infection and disseminate in NOD SCID Gamma (NSG) mice,which are deficient in both adaptive and most innate immune responses,suggesting that MCP5 plays an important role in evading host innate immunity. Moreover,NK cell depletion in C3H and SCID mice restored the infectivity of the mcp5 mutant,further highlighting MCP5’s role in evading NK cell-associated immunity. Co-culture assays with NK cells and macrophages revealed that the mcp5 mutant enhanced interferon-gamma production by NK cells. In the tick vector,the mcp5 mutants survived feeding but failed to transmit to mice. These findings reveal that MCP5,regulated by both the Rrp1 and Rrp2 pathways,is critical for establishing infection in mammalian hosts by evading NK cell-mediated host innate immunity and is important for the transmission of spirochetes from ticks to mammalian hosts. This work provides a foundation for further elucidation of chemotactic signals sensed by MCP5 that facilitate B . burgdorferi in evading host defenses. View Publication

CDK4/6 inhibitors have significantly improved the survival of patients with HR-positive/HER2-negative breast cancer,becoming a first-line treatment option. However,the development of resistance to these inhibitors is inevitable. To address this challenge,novel strategies are required to overcome resistance,necessitating a deeper understanding of its mechanisms. Recent research has identified several dysregulated genes in CDK4/6 inhibitors-resistant breast cancer,but the underlying mechanism is complex due to tumor heterogeneity and warrants further investigation. RNA sequencing and KEGG pathway analysis was carried out to identify the mainly dysregulated genes in CDK4/6 inhibitors-resistant breast cancer cells. The effects of CXCR4 knockdown and overexpression via siRNAs and plasmids transfection were examined by mammosphere formation,RT-qPCR,flow cytometry,MTT and colony formation assays. The regulation mechanisms were analyzed by RT-qPCR,western blotting and immunofluorescence experiments. Mouse xenografts were used to analyze the role of CXCR4 in regulation palbociclib sensitivity in vivo. Additionally,we collected the clinical samples and performed immunohistochemistry to analyze the clinical significance of CXCR4. In our study,we focused on cancer stem cells,a critical contributor to cancer metastasis and therapy resistance,and detected an upregulation of stemness in our established palbociclib-resistant ER-positive breast cancer cells. Additionally,our research pinpointed CXCR4 as a pivotal gene responsible for maintaining cancer stemness and promoting palbociclib resistance. Mechanistically,CXCR4 activates the WNT5A/β-catenin signaling pathway by enhancing the expression of WNT5A and β-catenin,facilitating the nuclear translocation of β-catenin protein. Targeting CXCR4 using siRNAs or small molecular inhibitors effectively reduces cancer stemness and reverses palbociclib resistance both in vitro and in vivo. Clinical sample analysis further underscores the overactivation of the CXCR4/WNT5A/β-catenin axis in palbociclib-resistant breast cancer,suggesting CXCR4 as a potential biomarker for predicting resistance to CDK4/6 inhibitors. Collectively,our study demonstrates that CXCR4 overexpression plays a vital role in maintaining breast cancer stemness and promoting resistance to CDK4/6 inhibitors through the activation of the WNT5A/β-catenin pathway. Targeting CXCR4 may offer a promising therapeutic approach for advanced CDK4/6 inhibitor-resistant ER-positive breast cancer. The online version contains supplementary material available at 10.1186/s13058-025-01965-3. View Publication

Functional cellular heterogeneity in tumours often underlies incomplete response to therapy and relapse. Previously,we demonstrated that the growth of the paediatric brain malignancy,sonic hedgehog subgroup medulloblastoma,is rooted in a dysregulated developmental hierarchy,the apex of which is defined by characteristically quiescent SOX2 + stem-like cells. Integrating gene expression and chromatin accessibility patterns in distinct cellular compartments,we identify the transcription factor Olig2 as regulating the stem cell fate transition from quiescence to activation,driving the generation of downstream neoplastic progenitors. Inactivation of Olig2 blocks stem cell activation and tumour output. Targeting this rare OLIG2-driven proliferative programme with a small molecule inhibitor,CT-179,dramatically attenuates early tumour formation and tumour regrowth post-therapy,and significantly increases median survival in vivo. We demonstrate that targeting transition from quiescence to proliferation at the level of the tumorigenic cell could be a pivotal medulloblastoma treatment strategy. Subject terms: Cancer stem cells,Mechanisms of disease,Cancer therapy View Publication

Cerebral organoids (COs) are valuable tools for studying the intricate interplay between glial cells and neurons in brain development and disease,including HIV-associated neuroinflammation. We developed a novel approach to generate microglia containing COs (CO-iMs) by co-culturing hematopoietic progenitors and inducing pluripotent stem cells. This approach allowed for the differentiation of microglia within the organoids concomitantly with the neuronal progenitors. Compared with conventional COs,CO-iMs were more efficient at generating CD45 + /CD11b + /Iba-1 + microglia and presented a physiologically relevant proportion of microglia (~ 7%). CO-iMs presented substantially increased expression of microglial homeostatic and sensome markers as well as markers for the complement cascade. CO-iMs are susceptible to HIV infection,resulting in a significant increase in several pro-inflammatory cytokines/chemokines,which are abrogated by the addition of antiretrovirals. Thus,CO-iM is a robust model for deciphering neuropathogenesis,neuroinflammation,and viral infections of brain cells in a 3D culture system. The online version contains supplementary material available at 10.1186/s12974-025-03353-2. View Publication

Macrophages are the major source of WNT ligands. However,the regulation of WNT expression in macrophages has not been studied. In the present study,we have discovered that activation of canonical β-Catenin signaling suppresses WNT expression in macrophages. EVs from these pre-conditioned macrophages promoted intestinal stem cell regeneration and mitigated intestinal injury. ChIP-seq analysis and validation studies using recombinant DNA construct expressing Luciferase reporter under WNT promoter (e.g. WNT5a and WNT9b) were conducted to demonstrate the involvement of β-Catenin in the transcriptional regulation of WNT expression. The regulatory role of β-Catenin in WNT expression in macrophages was examined by treating these cells with a Tankyrase inhibitor. In addition,the gene expressing β-Catenin was deleted in macrophages using Csf1r.iCre; Ctnnb1 fl/fl mice model. Both pharmacological and genetically modulated macrophages were examined for WNT expression and activity by qPCR and TCF/LEF luciferase assay respectively. Additionally,Csf1r.iCre; Ctnnb1 fl/fl mice were exposed to irradiation to compare the radiosensitivity with their wildtype littermate. Extracellular vesicles (EVs) were isolated from pre-conditioned WNT-enriched macrophages and infused in irradiated C57BL/6 and Lgr5/eGFP-IRES-Cre-ERT2 ; R26-ACTB-tdTomato-EGFP mice to determine the regenerative response of intestinal stem cell (ISC) and epithelial repair. Regenerative effects of EVs were also examined in mice model DSS induced colitis. ChIP-seq analysis and subsequent validation study suggested physical association of β-Catenin with WNT promoters to suppress WNT expression. Macrophage specific deletion of gene expressing β-Catenin or pharmacological inhibition of Tankyrase improves the WNT expression in macrophages several folds compared to control. Transfusion of these preconditioned macrophages or EVs from these cells delivers optimum level of morphogenic WNT to injured epithelium,activates ISC regeneration and mitigated radiation induced intestinal injury. Intestinal epithelium in Csf1r.iCre; Ctnnb1 fl/fl mice also showed radioresistance compared to wild type littermate. Moreover,EVs derived from WNT enriched macrophages can mitigate intestinal injury in mice model of DSS induced acute colitis. The study provides substantial evidence that macrophage-targeted modulation of canonical WNT signaling induces WNT expression in macrophages. Treatment with preconditioned macrophage derived WNT-enriched EVs can be a promising therapeutic approach against intestinal injury. The online version contains supplementary material available at 10.1186/s12964-025-02065-7. View Publication

Adipose-derived stromal cells (ASCs) possess significant regenerative potential,playing a key role in tissue repair and angiogenesis. During wound healing,ASC interacts with the extracellular matrix by recognizing arginylglycylaspartic acid (RGD) motifs,which are crucial for mediating these functions. This study investigates how RGD exposure influences ASC behavior,with a focus on angiogenesis. To mimic the wound-healing environment,ASC were cultured in a porcine gelatin sponge,an RGD-exposing matrix. Transcriptomics revealed that ASC cultured in gelatin exhibited an upregulated expression of genes associated with inflammation,angiogenesis,and tissue repair compared to ASC in suspension. Pro-inflammatory and pro-angiogenic factors,including IL-1,IL-6,IL-8,and VEGF,were significantly elevated. Functional assays further demonstrated that ASC-conditioned media enhanced endothelial cell migration,tubulogenesis,and reduced endothelial permeability,all critical processes in angiogenesis. Notably,ASC-conditioned media also promoted vasculogenesis in human vascular organoids. The inhibition of ASC-RGD interactions using the cyclic peptide cilengitide reversed these effects,underscoring the essential role of RGD-integrin interactions in ASC-mediated angiogenesis. These findings suggest that gelatin sponges enhance ASC’s regenerative and angiogenic properties via RGD-dependent mechanisms,offering promising therapeutic potential for tissue repair and vascular regeneration. Understanding how RGD modulates ASC behavior provides valuable insights into advancing cell-based regenerative therapies. View Publication

Animal models of the neuromuscular junction (NMJ) have been widely studied but exhibit critical differences from human biology limiting utility in drug and disease modelling. Challenges with scarcity,scalability,throughput,and ethical considerations further limit the suitability of animal models for preclinical screening. Engineered models have emerged as alternatives for studying NMJ functionality in response to genetic and/or pharmacological challenge. However,these models have faced challenges associated with their poorly scalable creation,sourcing suitable cells,and the extraction of reliable,quantifiable metrics. We present a turnkey iPSC-based model of the NMJ employing channelrhodopsin-2 expression within the motor neuron (MN) population driving muscle contraction in response to blue light. MNs co-cultured with engineered skeletal muscle tissues produced twitch forces of 34.7 ± 22.7 µN in response to blue light,with a response fidelity > 92 %. Histological analysis revealed characteristic punctate acetylcholine receptor staining co-localized with the presynaptic marker synaptic vesicle protein-2. Dose-response studies using botulinum neurotoxin showed loss of function in a dose- and time-dependent manner (EC50 - 0.11 ± 0.015 µg). Variability of the EC50 values between 2 different iPSC differentiations of both cell types and 2 users was less than 2 %. Further testing with the acute neurotoxins acetylcholine mustard and d-tubocurarine validated the biological relevance of the postsynaptic machinery of the model. This model marks a meaningful progression of 3D engineered models of the NMJ,providing engineered tissues at a throughput relevant to potency and screening applications with an abundant iPSC cell source and standardized hardware-software ecosystem allowing technology transfer across laboratories. View Publication

Telomeres are terminal protective chromosome structures. Genetic variants in genes coding for proteins required for telomere maintenance cause rare,life-threatening Telomere Biology Disorders (TBDs) such as dyskeratosis congenita,aplastic anemia or pulmonary fibrosis. The more frequently used mice strains have telomeres much longer than the human ones which question their use as in vivo models for TBDs. One mice model with shorter telomeres based on the CAST/EiJ mouse strain carrying a mutation in the Terc gene,coding for the telomerase RNA component,has been studied in comparison with C57BL/6J mice,carrying the same mutation and long telomeres. The possible alterations produced in lungs and the haematopoietic system,frequently affected in TBD patients,were determined at different ages of the mice. Homozygous mutant mice presented a very shortened life span,more notorious in the short-telomeres CAST/EiJ strain. The lungs of mutant mice presented a transitory increase in fibrosis and a significant decrease in the relative amount of the alveolar epithelial type 2 cells from six months of age. This decrease was larger in mutant homozygous animals but was also observed in heterozygous animals. On the contrary the expression of the senescence-related protein P21 increased from six months of age in mutant mice of both strains. The analysis of the haematopoietic system indicated a decrease in the number of megakaryocyte-erythroid progenitors in homozygous mutants and an increase in the clonogenic potential of bone marrow and LSK cells. Bone marrow cells from homozygous mutant animals presented decreasing in vitro expansion capacity. The alterations observed are compatible with precocious ageing of lung alveolar cells and the bone marrow cells that correlate with the alterations observed in TBD patients. The alterations seem to be more related to the genotype of the animals that to the basal telomere length of the strains although they are more pronounced in the short-telomere CAST/EiJ-derived strain than in C57BL/6J animals. Therefore,both animal models,at ages over 6–8 months,could represent valuable and convenient models for the study of TBDs and for the assay of new therapeutic products. View Publication

Induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) have greater potential for generating chondrocytes without hypertrophic and fibrotic phenotypes compared to bone marrow-derived mesenchymal stem/stromal cells (BMSCs). However,there is a lack of research demonstrating the use of autologous iMSCs for repairing articular chondral lesions in large animal models. In this study,we aimed to evaluate the effectiveness of autologous miniature pig (minipig) iMSC-chondrocyte (iMSC-Ch)-laden implants in comparison to autologous BMSC-chondrocyte (BMSC-Ch)-laden implants for cartilage repair in porcine femoral condyles. iMSCs and BMSCs were seeded into fibrin glue/nanofiber constructs and cultured with chondrogenic induction media for 7 days before implantation. To assess the regenerative capacity of the cells,19 skeletally mature Yucatan minipigs were randomly divided into microfracture control,acellular scaffold,iMSC,and BMSC subgroups. A cylindrical defect measuring 7 mm in diameter and 0.6 mm in depth was created on the articular cartilage surface without violating the subchondral bone. The defects were then left untreated or treated with acellular or cellular implants. Both cellular implant-treated groups exhibited enhanced joint repair compared to the microfracture and acellular control groups. Immunofluorescence analysis yielded significant findings,showing that cartilage treated with iMSC-Ch implants exhibited higher expression of COL2A1 and minimal to no expression of COL1A1 and COL10A1,in contrast to the BMSC-Ch-treated group. This indicates that the iMSC-Ch implants generated more hyaline cartilage-like tissue compared to the BMSC-Ch implants. Our findings contribute to filling the knowledge gap regarding the use of autologous iPSC derivatives for cartilage repair in a translational animal model. Moreover,these results highlight their potential as a safe and effective therapeutic strategy. The online version contains supplementary material available at 10.1186/s13287-025-04215-7. View Publication

Phospholipase C gamma 2,proline 522 to arginine (PLCγ2-P522R) is a protective variant that reduces the risk of Alzheimer’s disease (AD). Recently,it was shown to mitigate β-amyloid pathology in a 5XFAD mouse model of AD. Here,we investigated the protective functions of the PLCγ2-P522R variant in a less aggressive APP/PS1 mouse model of AD and assessed the underlying cellular mechanisms using mouse and human microglial models. The effects of the protective PLCγ2-P522R variant on microglial activation,AD-associated β-amyloid and neuronal pathologies,and behavioral changes were investigated in PLCγ2-P522R knock-in variant mice crossbred with APP/PS1 mice. Transcriptomic,proteomic,and functional studies were carried out using microglia isolated from mice carrying the PLCγ2-P522R variant. Finally,microglia-like cell models generated from human blood and skin biopsy samples of PLCγ2-P522R variant carriers were employed. The PLCγ2-P522R variant decreased β-amyloid plaque count and coverage in female APP/PS1 mice. Moreover,the PLCγ2-P522R variant promoted anxiety in these mice. The area of the microglia around β-amyloid plaques was also increased in mice carrying the PLCγ2-P522R variant,while β-amyloid plaque-associated neuronal dystrophy and the levels of certain cytokines,including IL-6 and IL-1β,were reduced. These alterations were revealed through [18F]FEPPA PET imaging and behavioral studies,as well as various cytokine immunoassays,transcriptomic and proteomic analyses,and immunohistochemical analyses using mouse brain tissues. In cultured mouse primary microglia,the PLCγ2-P522R variant reduced the size of lipid droplets. Furthermore,transcriptomic and proteomic analyses revealed that the PLCγ2-P522R variant regulated key targets and pathways involved in lipid metabolism,mitochondrial fatty acid oxidation,and inflammatory/interferon signaling in acutely isolated adult mouse microglia and human monocyte-derived microglia-like cells. Finally,the PLCγ2-P522R variant also increased mitochondrial respiration in human iPSC-derived microglia. These findings suggest that the PLCγ2-P522R variant exerts protective effects against β-amyloid and neuronal pathologies by increasing microglial responsiveness to β-amyloid plaques in APP/PS1 mice. The changes observed in lipid/fatty acid and mitochondrial metabolism revealed by the omics and metabolic assessments of mouse and human microglial models suggest that the protective effects of the PLCγ2-P522R variant are potentially associated with increased metabolic capacity of microglia. The online version contains supplementary material available at 10.1186/s12974-025-03387-6. View Publication

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are remarkably effective for treating EGFR-mutant non-small cell lung cancer (NSCLC). However,patients inevitably develop acquired drug resistance,resulting in recurrence or metastasis. It is important to identify novel effective therapeutic targets to reverse acquired TKI resistance. Bioinformatics analysis revealed that nicotinamide N-methyltransferase (NNMT) was upregulated in EGFR-TKI resistant cells and tissues via EGR1-mediated transcriptional activation. High NNMT levels were correlated with poor prognosis in EGFR-mutated NSCLC patients,which could promote resistance to EGFR-TKIs in vitro and in vivo. Mechanistically,NNMT catalyzed the conversion of nicotinamide to 1-methyl nicotinamide by depleting S-adenosyl methionine (the methyl group donor),leading to a reduction in H3K9 trimethylation (H3K9me3) and H3K27 trimethylation (H3K27me3) and subsequent epigenetic activation of EGR1 and ALDH3A1. In addition,ALDH3A1 activation increased lactic acid levels,which further promoted NNMT expression via p300-mediated histone H3K18 lactylation on its promoter. Thus,NNMT mediates the formation of a double positive feedback loop via EGR1 and lactate,EGR1/NNMT/EGR1 and NNMT/ALDH3A1/lactate/NNMT. Moreover,the combination of a small-molecule inhibitor for NNMT (NNMTi) and osimertinib exhibited promising potential for the treatment of TKI resistance in an NSCLC osimertinib-resistant xenograft model. The combined contribution of these two positive feedback loops promotes EGFR-TKI resistance in NSCLC. Our findings provide new insight into the role of histone methylation and histone lactylation in TKI resistance. The pivotal NNMT-mediated positive feedback loop may serve as a powerful therapeutic target for overcoming EGFR-TKI resistance in NSCLC. The online version contains supplementary material available at 10.1186/s12943-025-02285-y. View Publication