技术资料

Chemoresistance is associated with tumor relapse and unfavorable prognosis. Multiple mechanisms underlying chemoresistance have been elucidated,including stemness and DNA damage repair. Here,the involvement of the WNT receptor,FZD5,in ovarian cancer (OC) chemoresistance was investigated. OC cells were analyzed using in vitro techniques including cell transfection,western blot,immunofluorescence and phalloidin staining,CCK8 assay,colony formation,flowcytometry,real-time PCR,and tumorisphere formation. Pearson correlation analysis of the expression levels of relevant genes was conducted using data from the CCLE database. Further,the behavior of OC cells in vivo was assessed by generation of a mouse xenograft model. Functional studies in OC cells showed that FZD5 contributes to epithelial phenotype maintenance,growth,stemness,HR repair,and chemoresistance. Mechanistically,FZD5 modulates the expression of ALDH1A1,a functional marker for cancer stem-like cells,in a β-catenin-dependent manner. ALDH1A1 activates Akt signaling,further upregulating RAD51 and BRCA1,to promote HR repair. Taken together,these findings demonstrate that the FZD5-ALDH1A1-Akt pathway is responsible for OC cell survival,and targeting this pathway can sensitize OC cells to DNA damage-based therapy. The online version contains supplementary material available at 10.1186/s12964-024-01585-y. View Publication

Myeloperoxidase (MPO) is found almost exclusively in granulocytes and immature myeloid cells. It plays a key role in the innate immune system,catalysing the formation of reactive oxygen species that are important in anti‐microbial action,but MPO also oxidatively transforms the topoisomerase II (TOP2) poison etoposide to chemical forms that have elevated DNA damaging properties. TOP2 poisons such as etoposide are widely used anti‐cancer drugs,but they are linked to cases of secondary acute myeloid leukaemias through a mechanism that involves DNA damage and presumably erroneous repair leading to leukaemogenic chromosome translocations. This leads to the possibility that myeloperoxidase inhibitors could reduce the rate of therapy‐related leukaemia by protecting haematopoietic cells from TOP2 poison‐mediated genotoxic damage while preserving the anti‐cancer efficacy of the treatment. We show here that myeloperoxidase inhibition reduces etoposide‐induced TOP2B‐DNA covalent complexes and resulting DNA double‐strand break formation in primary ex vivo expanded CD34 + progenitor cells and unfractionated bone marrow mononuclear cells. Since MPO inhibitors are currently being developed as anti‐inflammatory agents this raises the possibility that repurposing of these potential new drugs could provide a means of suppressing secondary acute myeloid leukaemias associated with therapies containing TOP2 poisons. View Publication

Genetic deletion of Dusp1 eliminates CSF3R-induced leukemia. Inhibition of Dusp1 induces the expression of Bim and p53 in oncogenic context,resulting in selective demise of leukemic cells. View Publication

Brain organoids derived from human pluripotent stem cells are a promising tool for studying human neurodevelopment and related disorders. Here,we generated long-term cultures of cortical brain organoid slices (cBOS) grown at the air-liquid interphase from regionalized cortical organoids. We show that cBOS host mature neurons and astrocytes organized in complex architecture. Whole-cell patch-clamp demonstrated subthreshold synaptic inputs and action potential firing of neurons. Spontaneous intracellular calcium signals turned into synchronous large-scale oscillations upon combined disinhibition of NMDA receptors and blocking of GABA A receptors. Brief metabolic inhibition to mimic transient energy restriction in the ischemic brain induced reversible intracellular calcium loading of cBOS. Moreover,metabolic inhibition induced a reversible decline in neuronal ATP as revealed by ATeam1.03 YEMK . Overall,cBOS provide a powerful platform to assess morphological and functional aspects of human neural cells in intact minimal networks and to address the pathways that drive cellular damage during brain ischemia. Subject areas: Neuroscience,Cellular neuroscience,Stem cells research View Publication

Despite extensive research on microbiome alterations in ulcerative colitis (UC),the role of the constituent stable microbiota remains unclear. This study,employing 16S rRNA-gene sequencing,uncovers a persistent microbial imbalance in both active and quiescent UC patients compared to healthy controls. Using co-occurrence and differential abundance analysis,the study highlights microbial constituents,featuring Phocaeicola,Collinsella,Roseburia,Holdemanella,and Bacteroides,that are not affected during the course of UC. Co-cultivation experiments,utilizing commensal Escherichia coli and Phocaeicola vulgatus,were conducted with intestinal epithelial organoids derived from active UC patients and controls. These experiments reveal a tendency for a differential response in tight junction formation and maintenance in colonic epithelial cells,without inducing pathogen recognition and stress responses,offering further insights into the roles of these microorganisms in UC pathogenesis. These experiments also uncover high variation in patients’ response to the same bacteria,which indicate the need for more comprehensive,stratified analyses with an expanded sample size. This study reveals that a substantial part of the gut microbiota remains stable throughout progression of UC. Functional experiments suggest that members of core microbiota – Escherichia coli and Phocaeicola vulgatus – potentially differentially regulate the expression of tight junction gene in the colonic epithelium of UC patients and healthy individuals. The online version contains supplementary material available at 10.1186/s13099-024-00612-0. View Publication

Homology Directed Repair (HDR) enables precise genome editing,but the implementation of HDR-based therapies is hindered by limited efficiency in comparison to methods that exploit alternative DNA repair routes,such as Non-Homologous End Joining (NHEJ). In this study,we develop a functional,pooled screening platform to identify protein-based reagents that improve HDR in human hematopoietic stem and progenitor cells (HSPCs). We leverage this screening platform to explore sequence diversity at the binding interface of the NHEJ inhibitor i53 and its target,53BP1,identifying optimized variants that enable new intermolecular bonds and robustly increase HDR. We show that these variants specifically reduce insertion-deletion outcomes without increasing off-target editing,synergize with a DNAPK inhibitor molecule,and can be applied at manufacturing scale to increase the fraction of cells bearing repaired alleles. This screening platform can enable the discovery of future gene editing reagents that improve HDR outcomes. Subject terms: Targeted gene repair,Homologous recombination,High-throughput screening View Publication

Mutations in mexZ,encoding a negative regulator of the expression of the mexXY efflux pump genes,are frequently acquired by Pseudomonas aeruginosa at early stages of lung infection. Although traditionally related to resistance to the first-line drug tobramycin,mexZ mutations are associated with low-level aminoglycoside resistance when determined in the laboratory,suggesting that their selection during infection may not be necessarily,or only,related to tobramycin therapy. Here,we show that mexZ -mutated bacteria tend to accumulate inside the epithelial barrier of a human airway infection model,thus colonising the epithelium while being protected against diverse antibiotics. This phenotype is mediated by overexpression of lecA,a quorum sensing-controlled gene,encoding a lectin involved in P. aeruginosa tissue invasiveness. We find that lecA overexpression is caused by a disrupted equilibrium between the overproduced MexXY and another efflux pump,MexAB,which extrudes quorum sensing signals. Our results indicate that mexZ mutations affect the expression of quorum sensing-regulated pathways,thus promoting tissue invasiveness and protecting bacteria from the action of antibiotics within patients,something unnoticeable using standard laboratory tests. Subject terms: Antimicrobial resistance,Pathogens,Infection View Publication

Hepatocellular carcinoma (HCC) is widely recognized as a globally prevalent malignancy. Immunotherapy is a promising therapy for HCC patients. Increasing evidence suggests that lncRNAs are involved in HCC progression and immunotherapy. The study reveals the mechanistic role of long non‐coding RNA (lncRNA) FOXD1‐AS1 in regulating migration,invasion,circulating tumor cells (CTCs),epithelial‐mesenchymal transition (EMT),and immune escape in HCC in vitro. This study employed real‐time PCR (RT‐qPCR) to measure FOXD1‐AS1,miR‐615‐3p,and programmed death‐ligand 1 ( PD‐L1 ). The interactions of FOXD1‐AS1,miR‐615‐3p,and PD‐L1 were validated via dual‐luciferase reporter gene and ribonucleoprotein immunoprecipitation (RIP) assay. In vivo experimentation involves BALB/c mice and BALB/c nude mice to investigate the impact of HCC metastasis. The upregulation of lncRNA FOXD1‐AS1 in malignant tissues significantly correlates with poor prognosis. The investigation was implemented on the impact of lncRNA FOXD1‐AS1 on the migratory,invasive,and EMT of HCC cells. It has been observed that the lncRNA FOXD1‐AS1 significantly influences the generation and metastasis of M CTC in vivo analysis. In mechanistic analysis,lncRNA FOXD1‐AS1 enhanced immune escape in HCC via upregulation of PD‐L1,which acted as a ceRNA by sequestering miR‐615‐3p. Additionally,lncRNA FOXD1‐AS1 was found to modulate the EMT of CTCs through the activation of the PI3K/AKT pathway. This study presents compelling evidence supporting the role of lncRNA FOXD1‐AS1 as a miRNA sponge that sequesters miR‐655‐3p and protects PD‐L1 from suppression. View Publication

Neocortex expansion during evolution is linked to higher numbers of neurons,which are thought to result from increased proliferative capacity and neurogenic potential of basal progenitor cells during development. Here,we show that EREG,encoding the growth factor EPIREGULIN,is expressed in the human developing neocortex and in gorilla cerebral organoids,but not in the mouse neocortex. Addition of EPIREGULIN to the mouse neocortex increases proliferation of basal progenitor cells,whereas EREG ablation in human cortical organoids reduces proliferation in the subventricular zone. Treatment of cortical organoids with EPIREGULIN promotes a further increase in proliferation of gorilla but not of human basal progenitor cells. EPIREGULIN competes with the epidermal growth factor (EGF) to promote proliferation,and inhibition of the EGF receptor abrogates the EPIREGULIN-mediated increase in basal progenitor cells. Finally,we identify putative cis-regulatory elements that may contribute to the observed inter-species differences in EREG expression. Our findings suggest that species-specific regulation of EPIREGULIN expression may contribute to the increased neocortex size of primates by providing a tunable pro-proliferative signal to basal progenitor cells in the subventricular zone. View Publication

Picornaviruses are a leading cause of central nervous system (CNS) infections. While genotypes such as parechovirus A3 (PeV-A3) and echovirus 11 (E11) can elicit severe neurological disease,the highly prevalent PeV-A1 is not associated with CNS disease. Here,we expand our current understanding of these differences in PeV-A CNS disease using human brain organoids and clinical isolates of the two PeV-A genotypes. Our data indicate that PeV-A1 and A3 specific differences in neurological disease are not due to infectivity of CNS cells as both viruses productively infect brain organoids with a similar cell tropism. Proteomic analysis shows that PeV-A infection significantly alters the host cell metabolism. The inflammatory response following PeV-A3 (and E11 infection) is significantly more potent than that upon PeV-A1 infection. Collectively,our findings align with clinical observations and suggest a role for neuroinflammation,rather than viral replication,in PeV-A3 (and E11) infection. Subject terms: Infection,Central nervous system infections,Viral host response,Innate immunity View Publication

Dou et al. demonstrate that Parkinson’s disease-associated hyperactive LRRK2 decreases the trafficking of synaptic vesicle proteins within neurons by disrupting the regulation of the synaptic vesicle precursor protein RAB3A. Impaired delivery of synaptic proteins to presynaptic sites could contribute to the progression of debilitating non-motor PD symptoms. View Publication

The bone marrow adjusts blood cell production to meet physiological demands in response to insults. The spatial organization of normal and stress responses are unknown owing to the lack of methods to visualize most steps of blood production. Here we develop strategies to image multipotent haematopoiesis,erythropoiesis and lymphopoiesis in mice. We combine these with imaging of myelopoiesis 1 to define the anatomy of normal and stress haematopoiesis. In the steady state,across the skeleton,single stem cells and multipotent progenitors distribute through the marrow enriched near megakaryocytes. Lineage-committed progenitors are recruited to blood vessels,where they contribute to lineage-specific microanatomical structures composed of progenitors and immature cells,which function as the production sites for each major blood lineage. This overall anatomy is resilient to insults,as it was maintained after haemorrhage,systemic bacterial infection and granulocyte colony-stimulating factor (G-CSF) treatment,and during ageing. Production sites enable haematopoietic plasticity as they differentially and selectively modulate their numbers and output in response to insults. We found that stress responses are variable across the skeleton: the tibia and the sternum respond in opposite ways to G-CSF,and the skull does not increase erythropoiesis after haemorrhage. Our studies enable in situ analyses of haematopoiesis,define the anatomy of normal and stress responses,identify discrete microanatomical production sites that confer plasticity to haematopoiesis,and uncover unprecedented heterogeneity of stress responses across the skeleton. Subject terms: Bone marrow cells,Haematopoietic stem cells,Ageing,Imaging the immune system,Haematopoietic stem cells View Publication