技术资料

The introduction of antibody–drug conjugates represents a significant advancement in targeted therapy of acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). Our study aims to investigate the role of the DNA damage response pathway and the impact of PARP1 inhibition,utilizing talazoparib,on the response of AML and ALL cells to Gemtuzumab ozogamicin (GO) and Inotuzumab ozogamicin (INO),respectively. AML and ALL cells were treated with GO,INO and γ-calicheamicin in order to induce severe DNA damage and activate the G2/M cell-cycle checkpoint in a dose- and time-dependent manner. The efficacy of PARP1 inhibitors and,in particular,talazoparib in enhancing INO or GO against ALL or AML cells was assessed through measurements of cell viability,cell death,cell cycle progression,DNA damage repair,accumulation of mitotic DNA damage and inhibition of clonogenic capacity. We observed that both ALL and AML cell lines activate the G2/M cell-cycle checkpoint in response to γ-calicheamicin-induced DNA damage,highlighting a shared cellular response mechanism. Talazoparib significantly enhanced the efficacy of INO against ALL cell lines,resulting in reduced cell viability,increased cell death,G2/M cell-cycle checkpoint override,accumulation of mitotic DNA damage and inhibition of clonogenic capacity. Strong synergism was observed in primary ALL cells treated with the combination. In contrast,AML cells exhibited a heterogeneous response to talazoparib in combination with GO. Our findings suggest a potential link between the differential responses of ALL and AML cells to the drug combinations and the ability of talazoparibto override G2/M cell-cycle arrest induced by antibody–drug conjugates. PARP1 emerges as a key player in the response of ALL cells to INO and represents a promising target for therapeutic intervention in this leukemia setting. Our study sheds light on the intricate interplay between the DNA damage response pathway,PARP1 inhibition,and response of γ-calicheamicin-induced DNA damages in AML and ALL. These findings underscore the importance of targeted therapeutic strategies and pave the way for future research aimed at optimizing leukemia treatment approaches. The online version contains supplementary material available at 10.1186/s12967-024-05838-9. View Publication

Transplantation of engineered hematopoietic stem/progenitor cells (HSPCs) showed curative potential in patients affected by neurometabolic diseases treated in early stage. Favoring the engraftment and maturation of the engineered HSPCs in the central nervous system (CNS) could allow enhancing further the therapeutic potential of this approach. Here we unveil that HSPCs haplo-insufficient at the Cx3cr1 (Cx3cr1 −/+ ) locus are favored in central nervous system (CNS) engraftment and generation of microglia-like progeny cells (MLCs) as compared to wild type (Cx3cr1 +/+ ) HSPCs upon transplantation in mice. Based on this evidence,we have developed a CRISPR-based targeted gene addition strategy at the human CX3CR1 locus resulting in an enhanced ability of the edited human HSPCs to generate mature MLCs upon transplantation in immunodeficient mice,and in lineage specific,regulated and robust transgene expression. This approach,which benefits from the modulation of pathways involved in microglia maturation and migration in haplo-insufficient cells,may broaden the application of HSPC gene therapy to a larger spectrum of neurometabolic and neurodegenerative diseases. Subject terms: Targeted gene repair,Haematopoietic stem cells,Microglial cells View Publication

The effect of mechanical cues on cellular behaviour has been reported in multiple studies so far,and a specific aspect of interest is the role of mechanotransductive proteins in neuronal development. Among these,yes-associated protein (YAP) is responsible for multiple functions in neuronal development such as neuronal progenitor cells migration and differentiation while myocardin-related transcription factor A (MRTFA) facilitates neurite outgrowth and axonal pathfinding. Both proteins have indirectly intertwined fates via their signalling pathways. There is little literature investigating the roles of YAP and MRTFA in vitro concerning neurite outgrowth in mechanically confined microenvironments. Moreover,our understanding of their relationship in immature neurons cultured within engineered confined microenvironments is still lacking. In this study,we fabricated,via two-photon polymerization (2PP),2.5D microgrooves and 3D polymeric microchannels,with a diameter range from 5 to 30 μm. We cultured SH-SY5Y cells and differentiated them into immature neuron-like cells on both 2.5D and 3D microstructures to investigate the effect of mechanical confinement on cell morphology and protein expression. In 2.5D microgrooves,both YAP and MRTFA nuclear/cytoplasmic (N/C) ratios exhibited maxima in the 10 μm grooves indicating a strong relation with mechanical-stress-inducing confinement. In 3D microchannels,both proteins’ N/C ratio exhibited minima in presence of 5 or 10 μm channels,a behaviour that was opposite to the ones observed in the 2.5D microgrooves and that indicates how the geometry and mechanical confinement of 3D microenvironments are unique compared to 2.5D ones due to focal adhesion,actin,and nuclear polarization. Further,especially in presence of 2.5D microgrooves,cells featured an inversely proportional relationship between YAP N/C ratio and the average neurite length. Finally,we also cultured human induced pluripotent stem cells (hiPSCs) and differentiated them into cortical neurons on the microstructures for up to 2 weeks. Interestingly,YAP and MRTFA N/C ratios also showed a maximum around the 10 μm 2.5D microgrooves,indicating the physiological relevance of our study. Our results elucidate the possible differences induced by 2.5D and 3D confining microenvironments in neuronal development and paves the way for understanding the intricate interplay between mechanotransductive proteins and their effect on neural cell fate within engineered cell microenvironments. View Publication

Embryonic stem cells possess the remarkable ability to self-organize into blastocyst-like structures upon induction. These stem cell-based embryo models serve as invaluable platforms for studying embryogenesis and therapeutic developments. Nevertheless,the specific intrinsic regulators that govern this potential for blastoid formation remain unknown. Here we demonstrate an intrinsic program that plays a crucial role in both blastoids and blastocysts across multiple species. We first establish metrics for grading the resemblance of blastoids to mouse blastocysts,and identify the differential activation of gene regulons involved in lineage specification among various blastoid grades. Notably,abrogation of nuclear receptor subfamily 1,group H,member 2 (Nr1h2) drastically reduces blastoid formation. Nr1h2 activation alone is sufficient to rewire conventional ESC into a distinct pluripotency state,enabling them to form blastoids with enhanced implantation capacity in the uterus and contribute to both embryonic and extraembryonic lineages in vivo. Through integrative multi-omics analyses,we uncover the broad regulatory role of Nr1h2 in the transcriptome,chromatin accessibility and epigenome,targeting genes associated with embryonic lineage and the transposable element SINE-B1. The Nr1h2-centred intrinsic program governs and drives the development of both blastoids and early embryos. Subject terms: Embryonic stem cells,Pluripotency,Epigenomics View Publication

Liver cancer stem cells (LCSCs) are thought to drive the metastasis and recurrence,however,the heterogeneity of molecular markers of LCSCs has hindered the development of effective methods to isolate them. This study introduced an effective approach to isolate and culture LCSCs from human primary liver cancer (HPLC),leveraging mouse embryonic fibroblasts (MEFs) as feeder cells in conjunction with using defined medium. Isolated LCSCs were further characterized by multiple approaches. Transcriptome sequencing data analysis was conducted to identify highly expressed genes in LCSCs and classify different subtypes of liver cancers. Total sixteen cell strains were directly isolated from 24 tissues of three types of HPLC without sorting,seven of which could be maintained long-term culture as colony growth on MEFs,which is unique characteristics of stem cells. Even 10 of cloned cells formed the tumors in immunodeficient mice,indicating that those cloned cells were tumorgenic. The histologies and gene expression pattern of human xenografts were very similar to those of HPLC where these cloned cells were isolated. Moreover,putative markers of LCSCs were further verified to all express in cloned cells,confirming that these cells were LCSCs. These cloned LCSCs could be cryopreserved,and still maintained the feature of colony growth on MEFs after the recovery. Compared to suspension culture as conventional approach to culture LCSCs,our approach much better maintained stemness of LCSCs for a long time. To date,these cloned cells could be cultured on MEFs over 12 passages. Moreover,bioinformatics analysis of sequencing data revealed the gene expression profiles in LCSCs,and liver cancers were classified into two subtypes C1 and C2 based on genes associated with the prognosis of LCSCs. Patients of the C2 subtype,which is closely related to the extracellular matrix,were found to be sensitive to treatments such as Cisplatin,Axitinib,JAK1 inhibitors,WNT-c59,Sorafenib,and RO-3306. In summary,this effective approach offers new insights into the molecular landscape of human liver cancers,and the identification of the C2 subtype and its unique response to the treatment pave the way for the creation of more effective,personalized therapeutic strategies. The online version contains supplementary material available at 10.1186/s12967-024-05870-9. View Publication

Pericytes play a crucial role in controlling inflammation and vascular functions in the central nervous system,which are disrupted in Parkinson’s disease (PD). Still,there is a lack of studies on the impact of pericytes on neurodegenerative diseases,and their involvement in the pathology of PD is unclear. Our objective was to investigate the molecular and functional differences between healthy pericytes and pericytes with the LRRK2 G2019S mutation,which is one of the most common mutations associated with PD. Our study employed pericyte-like cells obtained from induced pluripotent stem cells produced from PD patients with the LRRK2 G2019S mutation as well as from healthy individuals. We examined the gene expression profiles of the cells and analyzed how the alterations reflect on their functionality. We have shown differences in the expression of genes related to inflammation and angiogenesis. Furthermore,we observe modified migration speed in PD pericyte-like cells as well as enhanced secretion of inflammatory mediators,such as soluble VCAM-1 and MCP-1,in these pericyte-like cells following exposure to proinflammatory stimuli. In summary,our findings support the notion that pericytes play a role in the inflammatory and vascular changes observed in PD. Further investigation of pericytes could provide valuable insight into understanding the pathogenesis of PD. The online version contains supplementary material available at 10.1186/s12987-024-00592-y. View Publication

Self-renewal programs in leukemia stem cells (LSCs) predict poor prognosis in patients with acute myeloid leukemia (AML). We identify CD4 + T cell-derived interleukin (IL)-21 as an important negative regulator of self-renewal of LSCs. IL-21/IL-21R signaling favors asymmetric cell division and differentiation in LSCs through the activation of p38-MAPK signaling,resulting in reduced LSC numbers and significantly prolonged survival in murine AML models. In human AML,serum IL-21 at diagnosis is identified as an independent positive prognostic biomarker for outcome and correlates with improved survival and higher complete remission rates in patients that underwent high-dose chemotherapy. IL-21 treatment inhibits primary LSC function and enhances the effect of cytarabine and CD70 CAR T cell treatment on LSCs in vitro . Low-dose IL-21 treatment prolongs the survival of AML mice in syngeneic and xenograft experiments. Therefore,promoting IL-21/IL-21R signaling on LSCs may be an approach to reduce stemness and increase differentiation in AML. View Publication

Ex vivo activation is a prerequisite to reaching adequate levels of gene editing by homology-directed repair (HDR) for hematopoietic stem and progenitor cell (HSPC)-based clinical applications. Here,we show that shortening culture time mitigates the p53-mediated DNA damage response to CRISPR-Cas9-induced DNA double-strand breaks,enhancing the reconstitution capacity of edited HSPCs. However,this results in lower HDR efficiency,rendering ex vivo culture necessary yet detrimental. Mechanistically,ex vivo activation triggers a multi-step process initiated by p38 mitogen-activated protein kinase (MAPK) phosphorylation,which generates mitogenic reactive oxygen species (ROS),promoting fast cell-cycle progression and subsequent proliferation-induced DNA damage. Thus,p38 inhibition before gene editing delays G1/S transition and expands transcriptionally defined HSCs,ultimately endowing edited cells with superior multi-lineage differentiation,persistence throughout serial transplantation,enhanced polyclonal repertoire,and better-preserved genome integrity. Our data identify proliferative stress as a driver of HSPC dysfunction with fundamental implications for designing more effective and safer gene correction strategies for clinical applications. View Publication

Global dissemination of SARS-CoV-2 Omicron sublineages has provided a sufficient opportunity for natural selection,thus enabling beneficial mutations to emerge. Characterisation of these mutations uncovers the underlying machinery responsible for the fast transmission of Omicron variants and guides vaccine development for combating the COVID-19 pandemic. Through systematic bioinformatics analysis of 496,606 sequences of Omicron variants,we obtained 40 amino acid substitutions that occurred with high frequency in the S protein. Utilising pseudoviruses and a trans -complementation system of SARS-CoV-2,we identified the effect of high-frequency mutations on viral infectivity and elucidated the molecular mechanisms. Finally,we evaluated the impact of a key emerging mutation on the immune protection induced by the SARS-CoV-2 VLP mRNA vaccine in a murine model. We identified a proline-to-leucine substitution at the 1263rd residue of the Spike protein,and upon investigating the relative frequencies across multiple Omicron sublineages,we found a trend of increasing frequency for P1263L. The substitution significantly enhances the capacity for S-mediated viral entry and improves the immunogenicity of a virus-like particle mRNA vaccine. Mechanistic studies showed that this mutation is located in the FERM binding motif of the cytoplasmic tail and impairs the interaction between the S protein and the Ezrin/Radixin/Moesin proteins. Additionally,this mutation facilitates the incorporation of S proteins into SARS-CoV-2 virions. This study offers mechanistic insight into the constantly increasing transmissibility of SARS-CoV-2 Omicron variants and provides a meaningful optimisation strategy for vaccine development against SARS-CoV-2. This study was supported by grants from the National Key Research and Development Plan of China (2021YFC2302405,2022YFC2303200,2021YFC2300200 and 2022YFC2303400),the National Natural Science Foundation of China (32188101,32200772,82422049,82241082,32270182,82372254,82271872,82341046,32100755 and 82102389),Shenzhen Medical Research Fund (B2404002,A2303036),the Shenzhen Bay Laboratory Startup Fund (21330111),Shenzhen San-Ming Project for Prevention and Research on Vector-borne Diseases (SZSM202211023),Yunnan Provincial Science and Technology Project at Southwest United Graduate School (202302AO370010). The New Cornerstone Science Foundation through the New Cornerstone Investigator Program,and the Xplorer Prize from Tencent Foundation. View Publication

A comprehensive understanding of the cardio-spleen-bone marrow immune cell axis is essential for elucidating the alterations occurring during the pathogenesis of diabetes mellitus (DM). This study investigates the dynamics of immune cell kinetics in DM after myocardial infarction (MI) over time. MI was induced in diabetic and healthy control groups using C57BL/N6 mice,with sacrifices occurring at days 1,3,7,and 28 post-MI to collect heart,peripheral blood (PB),spleen,and bone marrow (BM) samples. Cell suspensions from each organ were isolated and analyzed via flow cytometry. Additionally,the endothelial progenitor cell-colony-forming assay (EPC-CFA) was performed using mononuclear cells derived from BM,PB,and the spleen. The results indicated that,despite normal production in BM and the spleen,CD45+ cells were lower in the PB of DM mice at days 1 to 3. Further analysis revealed a reduction in total and pro-inflammatory neutrophils (N1s) in PB at days 1 to 3 and in the spleen at days 3 to 7 in DM mice,suggesting that DM-induced alterations in splenic neutrophils fail to meet the demand in PB and ischemic tissues. Infiltrating macrophages (total,M1,M2) were reduced at day 3 in the DM-ischemic heart,with total and M1 (days 1–3) and M2 (days 3–7) macrophages being significantly decreased in DM-PB compared to controls,indicating impaired macrophage recruitment and polarization in DM. Myeloid dendritic cells (mDCs) in the heart were higher from days 1 to 7,which corresponded with the enhanced recruitment of CD8+ cells from days 1 to 28 in the DM-infarcted myocardium. Total CD4+ cells decreased in DM-PB at days 1 to 3,suggesting a delayed adaptive immune response to MI. B cells were reduced in PB at days 1 to 3,in myocardium at day 3,and in the spleen at day 7,indicating compromised mobilization from BM. EPC-CFA results showed a marked decrease in definitive EPC colonies in the spleen and BM from days 1 to 28 in DM mice compared to controls in vitro,highlighting that DM severely impairs EPC colony-forming activity by limiting the differentiation of EPCs from primitive to definitive forms. Taking together,this study underscores significant disruptions in the cardio-spleen-bone marrow immune cell axis following MI in DM,revealing delayed innate and adaptive immune responses along with impaired EPC differentiation. View Publication

NAD(P)-dependent steroid dehydrogenase-like protein (NSDHL),which is involved in breast tumor growth and metastasis,has been implicated in the maintenance of cancer stem cells. However,its role in regulating breast cancer stem-like cells (BCSCs) remains unclear. We have previously reported the clinical significance of NSDHL in patients with estrogen receptor-positive (ER +) breast cancer. This study aimed to elucidate the molecular mechanisms by which NSDHL regulates the capacity of BCSCs in the ER + human breast cancer cell line,MCF-7. NSDHL knockdown suppressed tumor spheroid formation in MCF-7 human breast cancer cells grown on ultralow-attachment plates. RNA sequencing revealed that NSDHL knockdown induced widespread transcriptional changes in the MCF-7 spheroids. TGF-β signaling pathway was the most significantly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway (fold change ≥ 2,P ≤ 0.05) identified in NSDHL-knockdown MCF-7 spheroids compared with the control. In orthotopic tumor models injected with NSDHL-knockdown MCF-7 spheroids,tumor initiation and growth were strongly suppressed compared with those in the control. BCSC populations with CD44+/CD24- and CD49f+/EpCAM + phenotypes and high ALDH activity were decreased in NSDHL-knockdown MCF-7 spheroids and xenograft tumors relative to controls,along with decreased secretion of TGF-β1 and 3,phosphorylation of Smad2/3,and expression of SOX2. In RNA-sequencing data from The (TCGA) database,a positive correlation between the expression of NSDHL and SOX2 was found in luminal-type breast cancer specimens ( n = 998). Our findings revealed that NSDHL plays an important role in maintaining the BCSC population and tumor-initiating capacity of ER-positive MCF-7 spheroids,suggesting that NSDHL is an attractive therapeutic target for eliminating BCSCs,thus preventing breast cancer initiation and progression. Our findings suggest that NSDHL regulates the BCSC/tumor-initiating cell population in MCF-7 spheroids and xenograft tumors. The online version contains supplementary material available at 10.1186/s12885-024-13143-3. View Publication

Wound healing in adults largely depends on the functional state of multipotent mesenchymal stromal cells (MSCs). Human fetal tissues at the early stages of development are known to heal quickly with a full-quality restoration of the original structure. The differences in the molecular mechanisms that determine the functional activity of mesodermal cells in fetuses and adults remain virtually unknown. Using two independent human induced pluripotent stem cell (iPSC) lines,we examined the effects of the initial WNT and BMP activation on the differentiation of iPSCs via mesodermal progenitors into MSCs and highlighted the functions of these cells that are altered by the proinflammatory microenvironment. The WNT-induced mesoderm commitment of the iPSCs enhanced the expression of paraxial mesoderm (PM)-specific markers,while the BMP4-primed iPSCs exhibited increased levels of lateral mesoderm (LM)-specific genes. The inflammatory status and migration rate of the isogenic iPSC-derived mesoderm cells were assessed via gene expression analysis and scratch assay under the receptor-dependent activation of the proinflammatory IFN-γ or TNF-α signaling pathway. Reduced IDO1 and ICAM1 expression levels were detected in the WNT- and BMP-induced MSC progenitors compared to the isogenic MSCs in response to stimulation with IFN-γ and TNF-α. The WNT- and BMP-induced MSC progenitors exhibited a higher migration rate than isogenic MSCs upon IFN-γ exposure. The established isogenic cellular model will provide new opportunities to elucidate the mechanisms of regeneration and novel therapeutics for wound healing. View Publication