技术资料

Astrocytes are essential for the formation and maintenance of neural networks. However,a major technical challenge for investigating astrocyte function and disease-related pathophysiology has been the limited ability to obtain functional human astrocytes. Despite recent advances in human pluripotent stem cell (hPSC) techniques,primary rodent astrocytes remain the gold standard in coculture with human neurons. We demonstrate that a combination of leukemia inhibitory factor (LIF) and bone morphogenetic protein-4 (BMP4) directs hPSC-derived neural precursor cells to a highly pure population of astroglia in 28 d. Using single-cell RNA sequencing,we confirm the astroglial identity of these cells and highlight profound transcriptional adaptations in cocultured hPSC-derived astrocytes and neurons,consistent with their further maturation. In coculture with human neurons,multielectrode array recordings revealed robust network activity of human neurons in a coculture with hPSC-derived or rat astrocytes [3.63 ± 0.44 min −1 (hPSC-derived),2.86 ± 0.64 min −1 (rat); p = 0.19]. In comparison,we found increased spike frequency within network bursts of human neurons cocultured with hPSC-derived astrocytes [56.31 ± 8.56 Hz (hPSC-derived),24.77 ± 4.04 Hz (rat); p < 0.01],and whole-cell patch-clamp recordings revealed an increase of postsynaptic currents [2.76 ± 0.39 Hz (hPSC-derived),1.07 ± 0.14 Hz (rat); p < 0.001],consistent with a corresponding increase in synapse density [14.90 ± 1.27/100 μm 2 (hPSC-derived),8.39 ± 0.63/100 μm 2 (rat); p < 0.001]. Taken together,we show that hPSC-derived astrocytes compare favorably with rat astrocytes in supporting human neural network activity and maturation,providing a fully human platform for investigating astrocyte function and neuronal-glial interactions. View Publication

The growth factor Neuregulin-1 (NRG1) has pleiotropic roles in proliferation and differentiation of the stem cell niche in different tissues. It has been implicated in gut,brain and muscle development and repair. Six isoform classes of NRG1 and over 28 protein isoforms have been previously described. Here we report a new class of NRG1,designated NRG1-VII to denote that these NRG1 isoforms arise from a myeloid-specific transcriptional start site (TSS) previously uncharacterized. Long-read sequencing was used to identify eight high-confidence NRG1-VII transcripts. These transcripts presented major structural differences from one another,through the use of cassette exons and alternative stop codons. Expression of NRG1-VII was confirmed in primary human monocytes and tissue resident macrophages and induced pluripotent stem cell-derived macrophages (iPSC-derived macrophages). Isoform switching via cassette exon usage and alternate polyadenylation was apparent during monocyte maturation and macrophage differentiation. NRG1-VII is the major class expressed by the myeloid lineage,including tissue-resident macrophages. Analysis of public gene expression data indicates that monocytes and macrophages are a primary source of NRG1. The size and structure of class VII isoforms suggests that they may be more diffusible through tissues than other NRG1 classes. However,the specific roles of class VII variants in tissue homeostasis and repair have not yet been determined. The online version contains supplementary material available at 10.1186/s12864-024-10723-2. View Publication

Intermediate-length repeat expansions in ATAXIN-2 (ATXN2) are the strongest genetic risk factor for amyotrophic lateral sclerosis (ALS). At the molecular level,ATXN2 intermediate expansions enhance TDP-43 toxicity and pathology. However,whether this triggers ALS pathogenesis at the cellular and functional level remains unknown. Here,we combine patient-derived and mouse models to dissect the effects of ATXN2 intermediate expansions in an ALS background. iPSC-derived motor neurons from ATXN2-ALS patients show altered stress granules,neurite damage and abnormal electrophysiological properties compared to healthy control and other familial ALS mutations. In TDP-43 Tg -ALS mice,ATXN2-Q33 causes reduced motor function,NMJ alterations,neuron degeneration and altered in vitro stress granule dynamics. Furthermore,gene expression changes related to mitochondrial function and inflammatory response are detected and confirmed at the cellular level in mice and human neuron and organoid models. Together,these results define pathogenic defects underlying ATXN2-ALS and provide a framework for future research into ATXN2-dependent pathogenesis and therapy. Subject terms: Amyotrophic lateral sclerosis,Molecular neuroscience,Cellular neuroscience View Publication

Hypomethylating agents (HMAs) are frontline therapies for Myelodysplastic Neoplasms (MDS) and Acute Myeloid Leukemia (AML). However,acquired resistance and treatment failure are commonplace. To address this,we perform a genome-wide CRISPR-Cas9 screen in a human MDS-derived cell line,MDS-L,and identify TOPORS as a loss-of-function target that synergizes with HMAs,reducing leukemic burden and improving survival in xenograft models. We demonstrate that depletion of TOPORS mediates sensitivity to HMAs by predisposing leukemic blasts to an impaired DNA damage response (DDR) accompanied by an accumulation of SUMOylated DNMT1 in HMA-treated TOPORS-depleted cells. The combination of HMAs with targeting of TOPORS does not impair healthy hematopoiesis. While inhibitors of TOPORS are unavailable,we show that inhibition of protein SUMOylation with TAK-981 partially phenocopies HMA-sensitivity and DDR impairment. Overall,our data suggest that the combination of HMAs with inhibition of SUMOylation or TOPORS is a rational treatment option for High-Risk MDS (HR-MDS) or AML. Subject terms: Myelodysplastic syndrome,Acute myeloid leukaemia,Sumoylation View Publication

DNA hypomethylating agents (HMAs) are used for the treatment of myeloid malignancies,although their therapeutic effects have been unsatisfactory. Here we show that CRISPR-Cas9 screening reveals that knockout of topoisomerase 1-binding arginine/serine-rich protein ( TOPORS ),which encodes a ubiquitin/SUMO E3 ligase,augments the efficacy of HMAs on myeloid leukemic cells with little effect on normal hematopoiesis,suggesting that TOPORS is involved in resistance to HMAs. HMAs are incorporated into the DNA and trap DNA methyltransferase-1 (DNMT1) to form DNA-DNMT1 crosslinks,which undergo SUMOylation,followed by proteasomal degradation. Persistent crosslinking is cytotoxic. The TOPORS RING finger domain,which mediates ubiquitination,is responsible for HMA resistance. In TOPORS knockout cells,DNMT1 is stabilized by HMA treatment due to inefficient ubiquitination,resulting in the accumulation of unresolved SUMOylated DNMT1. This indicates that TOPORS ubiquitinates SUMOylated DNMT1,thereby promoting the resolution of DNA-DNMT1 crosslinks. Consistently,the ubiquitination inhibitor,TAK-243,and the SUMOylation inhibitor,TAK-981,show synergistic effects with HMAs through DNMT1 stabilization. Our study provides a novel HMA-based therapeutic strategy that interferes with the resolution of DNA-DNMT1 crosslinks. Subject terms: Myelodysplastic syndrome,Myelodysplastic syndrome View Publication

Three-dimensionality (3D) was proven essential for developing reliable models for different anatomical compartments and many diseases. However,the neuronal compartment still poses a great challenge as we still do not understand precisely how the brain computes information and how the complex chain of neuronal events can generate conscious behavior. Therefore,a comprehensive model of neuronal tissue has not yet been found. The present work was conceived in this framework: we aimed to contribute to what must be a collective effort by filling in some information on possible 3D strategies to pursue. We compared directly different kinds of scaffolds (i.e.,PDMS sponges,thermally crosslinked hydrogels,and glass microbeads) in their effect on neuronal network activity recorded using micro-electrode arrays. While the overall rate of spiking activity remained consistent,the type of scaffold had a notable impact on bursting dynamics. The frequency,density of bursts,and occurrence of random spikes were all affected. The examination of inter-burst intervals revealed distinct burst generation patterns unique to different scaffold types. Network burst propagation unveiled divergent trends among configurations. Notably,it showed the most differences,underlying that functional variations may arise from a different 3D spatial organization. This evidence suggests that not all 3D neuronal constructs can sustain the same level of richness of activity. Furthermore,we commented on the reproducibility,efficacy,and scalability of the methods,where the beads still offer superior performances. By comparing different 3D scaffolds,our results move toward understanding the best strategies to develop functional 3D neuronal units for reliable pre-clinical studies. View Publication

Despite advances in breast cancer screening and treatment,prognosis for metastatic disease remains dismal at 30% five-year survival. This is due,in large,to the failure of current therapeutics to target properties unique to metastatic cells. One of the drivers of metastasis is miR-10b,a small noncoding RNA implicated in cancer cell invasion,migration,viability,and proliferation. We have developed a nanodrug,termed MN-anti-miR10b,that delivers anti-miR-10b antisense oligomers to cancer cells. In mouse models of metastatic triple-negative breast cancer,MN-anti-miR10b has been shown to prevent onset of metastasis and eliminate existing metastases in combination with chemotherapy,even after treatment has been stopped. Recent studies have implicated miR-10b in conferring stem cell-like properties onto cancer cells,such as chemoresistance. In this study,we show transcriptional evidence that inhibition of miR-10b with MN-anti-miR10b activates developmental processes in cancer cells and that stem-like cancer cells have increased miR-10b expression. We then demonstrate that treatment of breast cancer cells with MN-anti-miR10b reduces their stemness,confirming that these properties make metastatic cells susceptible to the nanodrug actions. Collectively,these findings indicate that inhibition of miR-10b functions to impair breast cancer cell stemness,positioning MN-anti-miR10b as an effective treatment option for stem-like breast cancer subtypes. View Publication

Programmed cell death 1 (PD-1) is a premier cancer drug target for immune checkpoint blockade (ICB). Because PD-1 receptor inhibition activates tumor-specific T-cell immunity,research has predominantly focused on T-cell-PD-1 expression and its immunobiology. In contrast,cancer cell-intrinsic PD-1 functional regulation is not well understood. Here,we demonstrate induction of PD-1 in melanoma cells via type I interferon receptor (IFNAR) signaling and reversal of ICB efficacy through IFNAR pathway inhibition. Treatment of melanoma cells with IFN-α or IFN-β triggers IFNAR-mediated Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling,increases chromatin accessibility and resultant STAT1/2 and IFN regulatory factor 9 (IRF9) binding within a PD-1 gene enhancer,and leads to PD-1 induction. IFNAR1 or JAK/STAT inhibition suppresses melanoma-PD-1 expression and disrupts ICB efficacy in preclinical models. Our results uncover type I IFN-dependent regulation of cancer cell-PD-1 and provide mechanistic insight into the potential unintended ICB-neutralizing effects of widely used IFNAR1 and JAK inhibitors. Subject terms: Melanoma,Cancer immunotherapy,Tumour immunology View Publication

Riboflavin transporter deficiency type 2 (RTD2) is a rare neurodegenerative autosomal recessive disease caused by mutations in the SLC52A2 gene encoding the riboflavin transporters,RFVT2. Riboflavin (Rf) is the precursor of FAD (flavin adenine dinucleotide) and FMN (flavin mononucleotide),which are involved in different redox reactions,including the energetic metabolism processes occurring in mitochondria. To date,human induced pluripotent stem cells (iPSCs) have given the opportunity to characterize RTD2 motoneurons,which reflect the most affected cell type. Previous works have demonstrated mitochondrial and peroxisomal altered energy metabolism as well as cytoskeletal derangement in RTD2 iPSCs and iPSC-derived motoneurons. So far,no attention has been dedicated to astrocytes. Here,we demonstrate that in vitro differentiation of astrocytes,which guarantee trophic and metabolic support to neurons,from RTD2 iPSCs is not compromised. These cells do not exhibit evident morphological differences nor significant changes in the survival rate when compared to astrocytes derived from iPSCs of healthy individuals. These findings indicate that differently from what had previously been documented for neurons,RTD2 does not compromise the morpho-functional features of astrocytes. View Publication

PU.1 ( SPI1 ) is pivotal in hematopoiesis,yet its role in human endothelial-to-hematopoietic transition (EHT) remains unclear. Comparing human in vivo and in vitro EHT transcriptomes revealed SPI1 ’s regulatory role. Knocking down SPI1 during in vitro EHT led to a decrease in the generation of hematopoietic progenitor cells (HPCs) and their differentiation potential. Through multi-omic analysis,we identified KLF1 and LYL1 - transcription factors specific to erythroid/myeloid and lymphoid cells,respectively - as downstream targets of SPI1 . Overexpressing KLF1 or LYL1 partially rescues the SPI1 knockdown-induced reduction in HPC formation. Specifically,KLF1 overexpression restores myeloid lineage potential,while LYL1 overexpression re-establishes lymphoid lineage potential. We also observed a SPI1 - LYL1 axis in the regulatory network in in vivo EHT. Taken together,our findings shed new light on the role of SPI1 in regulating lineage commitment during EHT,potentially contributing to the heterogeneity of hematopoietic stem cells (HSCs). Subject areas: Biological sciences,Molecular biology,Molecular interaction,Cell biology; View Publication

Chemotherapy-induced peripheral neuropathy (CIPN) is a disabling side effect of cancer chemotherapy that can often limit treatment options for cancer patients or have life-long neurodegenerative consequences that reduce the patient’s quality of life. CIPN is caused by the detrimental actions of various chemotherapeutic agents on peripheral axons. Currently,there are no approved preventative measures or treatment options for CIPN,highlighting the need for the discovery of novel therapeutics and improving our understanding of disease mechanisms. In this study,we utilized human-induced pluripotent stem cell (hiPSC)-derived motor neurons as a platform to mimic axonal damage after treatment with vincristine,a chemotherapeutic used for the treatment of breast cancers,osteosarcomas,and leukemia. We screened a total of 1902 small molecules for neuroprotective properties in rescuing vincristine-induced axon growth deficits. From our primary screen,we identified 38 hit compounds that were subjected to secondary dose response screens. Six compounds showed favorable pharmacological profiles – AZD7762,A-674563,Blebbistatin,Glesatinib,KW-2449,and Pelitinib,all novel neuroprotectants against vincristine toxicity to neurons. In addition,four of these six compounds also showed efficacy against vincristine-induced growth arrest in human iPSC-derived sensory neurons. In this study,we utilized high-throughput screening of a large library of compounds in a therapeutically relevant assay. We identified several novel compounds that are efficacious in protecting different neuronal subtypes from the toxicity induced by a common chemotherapeutic agent,vincristine which could have therapeutic potential in the clinic. The online version contains supplementary material available at 10.1007/s00018-024-05340-x. View Publication

Olanzapine (OLZ) reverses chronic stress-induced anxiety. Chronic stress promotes cancer development via abnormal neuro-endocrine activation. However,how intervention of brain-body interaction reverses chronic stress-induced tumorigenesis remains elusive. Kras LSL−G12D/WT lung cancer model and LLC1 syngeneic tumor model were used to study the effect of OLZ on cancer stemness and anxiety-like behaviors. Cancer stemness was evaluated by qPCR,western-blotting,immunohistology staining and flow-cytometry analysis of stemness markers,and cancer stem-like function was assessed by serial dilution tumorigenesis in mice and extreme limiting dilution analysis in primary tumor cells. Anxiety-like behaviors in mice were detected by elevated plus maze and open field test. Depression-like behaviors in mice were detected by tail suspension test. Anxiety and depression states in human were assessed by Hospital Anxiety and Depression Scale (HADS). Chemo-sensitivity of lung cancer was assessed by in vivo syngeneic tumor model and in vitro CCK-8 assay in lung cancer cell lines. In this study,we found that OLZ reversed chronic stress-enhanced lung tumorigenesis in both Kras LSL−G12D/WT lung cancer model and LLC1 syngeneic tumor model. OLZ relieved anxiety and depression-like behaviors by suppressing neuro-activity in the mPFC and reducing norepinephrine (NE) releasing under chronic stress. NE activated ADRB2-cAMP-PKA-CREB pathway to promote CLOCK transcription,leading to cancer stem-like traits. As such,CLOCK-deficiency or OLZ reverses NE/chronic stress-induced gemcitabine (GEM) resistance in lung cancer. Of note,tumoral CLOCK expression is positively associated with stress status,serum NE level and poor prognosis in lung cancer patients. We identify a new mechanism by which OLZ ameliorates chronic stress-enhanced tumorigenesis and chemoresistance. OLZ suppresses mPFC-NE-CLOCK axis to reverse chronic stress-induced anxiety-like behaviors and lung cancer stemness. Decreased NE-releasing prevents activation of ADRB2-cAMP-PKA-CREB pathway to inhibit CLOCK transcription,thus reversing lung cancer stem-like traits and chemoresistance under chronic stress. The online version contains supplementary material available at 10.1186/s12964-024-01747-y. View Publication