技术资料

Different innate immune cell types are known to release extracellular traps (ETs) in response to invasive pathogens,including parasites. These ETs function to trap,immobilize,and eventually kill pathogens. In line with this,monocytes and macrophages have been shown to release ETs,known as monocyte/macrophage extracellular traps (METs). Toxoplasma gondii (T. gondii) is an apicomplexan zoonotic parasite that infects humans and homeothermic animals. While most studies have focused on prolonged exposure of immune cells to T. gondii,this study characterized the early innate immune reaction of mononuclear phagocytes to vital T. gondii tachyzoites. Methods: Primary human and bovine monocytes,monocytic THP-1 cells,and THP-1 cell-derived macrophages (M0-,M1-,and M2-like) were exposed to T. gondii tachyzoites for 4 h. Scanning electron microscopy (SEM),transmission electron microscopy (TEM),immunofluorescencemicroscopy,and confocal microscopy were used to visualize cell activation and the presence of METs. Additionally,the release of pro-inflammatory cytokines interleukin (IL)-1β and IL-6,and expression of Toll-like receptor (TLR) 2 and TLR4 were analyzed. Results and discussion: Microscopic analysis illustrated the activation of all cell types tested within 4 h of exposure to T. gondii tachyzoites. Numerous tachyzoites were found intracellularly in THP-1 cell-derived M1-like macrophages. Furthermore,the co-localization of extracellular DNA (extDNA) and histones in extracellular web-like fibers proved classical characteristics of extruded T. gondii-induced METs,although this was a rare event. In primary human monocytes,an increased release of IL-1β and IL-6 was observed following exposure to T. gondii tachyzoites. When co-stimulated with lipopolysaccharide (LPS),primary human monocytes showed an enhanced release of IL-1β and IL-6 in response to T. gondii. In contrast to monocytic THP-1 cells,THP-1 cell-derived M1-like macrophages released IL-1β in response to T. gondii tachyzoite exposure. When additionally stimulated by LPS,all THP-1 cell-derived macrophages showed an enhanced release of IL-1β,and monocytic THP-1 cells an increased release of IL-6 in response to T. gondii tachyzoites. This study provides insights into the early innate immune response of human and bovine mononuclear phagocytes to T. gondii. While cytokine secretion was prominent,MET formation was rare in the early response (i.e. < 4 h of exposure) to T. gondii tachyzoites. View Publication

Pancreatic β cells derived from human induced pluripotent stem cells (hiPSCs) represent a promising therapeutic avenue in regenerative medicine for diabetes treatment. However,current differentiation protocols lack the specificity and efficiency required to reliably produce fully functional β cells,limiting their clinical applicability. Epigenetic barriers,such as histone modifications,may hinder proper differentiation and the acquisition of essential maturation markers in these cells. Methods: hiPSCs were cultured under feeder-free conditions and subjected to lentiviral transduction with shRNA constructs to silence KDM4A. Differentiation into pancreatic β-like cells was performed using stepwise protocols,with or without doxycycline supplementation,to evaluate the effect of KDM4A suppression. Gene expression was quantified by RT-qPCR,protein expression was assessed by western blotting and immunofluorescence,and functional insulin release was determined by glucose-stimulated insulin secretion (GSIS) assays. Statistical analysis was conducted using unpaired two-tailed Student’s t-tests,with significance set at p < 0.05. Results: A reduction in pancreatic development proteins was observed in the different differentiation states evaluated,after blocking KDM4A expression. Knockdown of KDM4A significantly reduced the expression of pancreatic β-cell genes,such as PDX1,Nkx6.1,and Ins,by 50% compared to WT iPSCs differentiated under the same conditions. Similarly,glucose-stimulated insulin secretion was reduced by approximately 80% in KDM4A-deficient β-like cells. Conclusions: These results emphasize the critical role of histone demethylation in hiPSC differentiation toward β cells. Our findings identify KDM4A as a key epigenetic regulator,suggesting that its modulation could enhance the generation of functional β cells for regenerative medicine in diabetes. View Publication

Chemotherapy-induced peripheral neuropathy (CIPN) affects up to two-thirds of cancer patients undergoing cytotoxic chemotherapy. Here,we used human iPSC-derived sensory neurons (iPSC-DSN) to model CIPN in vitro. Administration of various chemotherapeutic agents (i.e.,paclitaxel,vincristine,bortezomib and cisplatin) at clinically applicable concentrations resulted in reduced cell viability,axonal degeneration,electrophysiological dysfunction and increased levels of phosphorylated c-Jun in iPSC-DSN. Transcriptomic analyses revealed that the upregulation of c-Jun strongly correlated with the expression of genes of neuronal injury,apoptosis and inflammatory signatures. To test whether c-Jun plays a central role in the development of CIPN,we applied the small molecule inhibitor of the Jun N-terminal kinase,SP600125,to iPSC-DSN treated with neurotoxic chemotherapy. c-Jun inhibition prevented chemotherapy-induced neurotoxicity by preserving cell viability,axonal integrity and electrophysiological function of iPSC-DSN. These findings identify c-Jun as a key mediator of CIPN pathophysiology across multiple drug types and present preclinical evidence that c-Jun inhibition is an attractive therapeutic target to prevent CIPN. View Publication

Proteomics of dystrophic muscle samples is limited by the amount of protein that can be extracted from patient biopsies. Cells and tissues derived from patient-derived induced pluripotent stem cells (iPSCs) can be an expandable alternative source. We have patterned iPSCs from three Duchenne muscular dystrophy (DMD) patient lines into skeletal muscle cells using a two-dimensional as well as our three-dimensional organoid differentiation system. Probes with sufficient protein amounts could be extracted and prepared for mass spectrometry. In total,3007 proteins in 2D and 2709 proteins in 3D were detected in DMD patient probes. A total of 83 proteins in 2D and 338 proteins in 3D can be described as differentially expressed between DMD and control patient probes in a post hoc test. We have identified and we propose Myosin-9,Collagen 18A,Tropomyosin 1,BASP1,RUVBL1,and NCAM1 as proteins specifically altered in their expression in DMD for further investigation. Proteomics of skeletal muscle organoids resulted in greater consistency of results between cell lines in comparison to the two-dimensional myogenic differentiation protocol. View Publication

Osteoporosis (OP) could lead to the alteration of bone marrow microenvironment and non-homeostasis of hematopoiesis,which could increase the incidence of hematologic malignancies. However,whether myeloid-biased hematopoiesis occurred and contributed to the leukemogenesis under the condition of OP remains unclear. Results: This study successfully induced a mouse model for OP by hindlimb unloading,which shows increased myeloid cells and decreased B cells in the peripheral blood (PB). Furthermore,our study demonstrates that the myeloid-biased subset of HSPCs (hematopoietic stem and progenitor cells) with reduced differentiation and apoptosis,including multipotent progenitor 3 (MPP3) and granulocyte-monocyte progenitors (GMPs),were expanded in the OP mice. The expansion of myeloid-biased HSPCs contributes to the accumulation of HSPCs in the bone marrow and increased myeloid cells in the PB of OP mice. In the expanded pool of HSPCs,OP mice specifically enriched subsets were identified and profiled by single cell RNA-seq,including subHSCs from primitive HSCs,MPP3-1 from MPP3,GMP5 from GMPs,MkP2 from megakaryocyte progenitors and EryP1 from erythrocyte progenitors. Meanwhile,those OP-HU mice enriched subsets shared significantly up- and down-regulated genes enriched in chromatin modification and cell differentiation and apoptosis such as Bromodomain-containing protein 4 (Brd4),encoding an important chromatin remodeling protein,and Proteinase 3 (Prtn3). Moreover,the specific transcription factors corresponding to the expansion of subHSCs,MPP3-1,GMP5 and EryP1 in OP-HU mice were identified as Zfp951,Nfic,Maz and Ezh2. Finally,inhibition of BRD4 in vivo could partially restore the phenotype of OP-HU mice and the expression of genes regulating HSPC expansion,differentiation and apoptosis. Conclusions: First of all,our study shows that OP could induce the unbalanced hematopoiesis and enhances the myeloid-biased hematopoiesis. Secondly,OP mice enriched subsets of HSPCs were identified and characterized with enhanced chromatin remodeling,reduced differentiation and resistance to apoptosis. Finally,this study demonstrate that Brd4 regulated gene programs endow the myeloid-biased subsets of HSPCs with tumor cell-like characters in OP mice,which may increase the incidence of the leukemic evolution. This study sheds light on the importance for the prevention of myeloid leukemogenesis in human with OP. View Publication

Effective therapies for Alzheimer’s disease (AD) remain to be developed. APOE4 is the strongest genetic risk factor for late-onset AD. Pericyte degeneration and blood–brain barrier (BBB) disruption are thought to be early biomarkers of AD and contribute to cognitive decline in APOE4 carriers,representing potential therapeutic targets. Our previous studies have shown that pericyte transplantation is one of the most effective strategies for BBB restoration,exhibiting great therapeutic potential for APOE4-related BBB damage and AD phenotypes. Methods: APOE4/4 mice were treated with pericytes derived from APOE3/3 human induced pluripotent stem cells (hiPSCs). Behavioral tests,AD pathologies,and BBB integrity were assessed. Subsequently,temporal and spatial distribution of the transplanted pericytes was analyzed using tdTomato+ lentivirus labeling. Next,therapeutic effects of apoptotic vesicles (ApoVs) generated from APOE3/3 pericytes were evaluated in APOE4/4 pericytes in vitro. Additionally,transcriptomic and proteomic profiling were performed to identify key effector molecules in pericyte-derived ApoVs. Finally,the therapeutic effects of ApoVs derived from pericytes were evaluated in APOE4/4 mice. Results: Early,multiple transplantations of pericytes derived from APOE3/3 hiPSCs robustly rescued cognitive decline and AD pathologies,restored BBB integrity,and prevented in situ pericyte degeneration in aged APOE4/4 mice. Intriguingly,ApoVs released from the infused cells,rather than the transplanted pericytes,were predominantly distributed in the brain,which were ingested by in situ APOE4/4 pericytes and then promoted functional recovery. We further characterized insulin growth factor-2 (IGF-2) as a key factor in APOE3/3 pericyte-derived ApoVs. Infusion of the in vitro generated ApoVs from APOE3/3 pericytes demonstrated distinct therapeutic effects in APOE4/4 mice,which were reversed by IGF2 knockout. Conclusions: APOE3/3 pericytes or APOE3/3 pericyte-derived IGF2-rich ApoVs may offer promising therapeutic strategies for APOE4-associated AD. View Publication

Interleukin-1 receptor accessory protein (IL1RAP) is selectively expressed on both bulk blasts and leukemic stem cells (LSCs) in acute myeloid leukemia (AML),while its expression is virtually absent on normal hematopoietic stem cells (HSCs),making it an appealing target for chimeric antigen receptor (CAR) T cell therapy. Methods: We developed a novel IL1RAP-targeting CAR-T cells using a single-chain Fab (24scFab) fused to CD28 and CD3ζ costimulatory domains. CAR-T cells with a mutated IL1RAP-binding paratope were also generated as a control by introducing two point-mutations in the complementarity determining region (CDR) loops of the 24scFab domain. We tested the CAR-T cells in cell line-derived (CD) and patient-derived (PD) xenografts (X). To address persistence and activity of IL1RAP CAR-T cells,we then tested two approaches. First,we mutated two of the three immunoreceptor tyrosine-based activation motifs (ITAMs) within the CD3ζ domain (i.e.,IL1RAP-1XX CAR-T). Second,we co-administered a synthetic miR-142 mimic (M-miR-142),previously shown to enhance T cell antileukemic activity,with IL1RAP CAR-T cells to AML xenografted mice. Results: IL1RAP CAR-T cells demonstrated a potent antileukemic activity in both AML CDX and PDX models. Target specificity was confirmed by the complete loss of function of IL1RAP-mutated CAR-T cells. IL1RAP-1XX CAR-T cells improved T cell persistence in vitro but failed to demonstrate therapeutic benefit compared with IL1RAP CAR-T cells in vivo. We previously reported that leukemic cell growth suppresses miR-142 biogenesis,thereby hindering the metabolic switch and impairing host T cell antileukemic activity; this was rescued by administration of M-miR-142. Thus,we hypothesized a similar impact of leukemic cells on CAR-T and that M-miR-142 treatment could rescue it and enhance the IL1RAP CAR-T cell antileukemic activity. We showed that both CDXs and PDXs receiving M-miR-142 and IL1RAP CAR-T lived significantly longer than those receiving scrambled oligonucleotide and IL1RAP CAR-T or mutated CAR-T controls (median survival of PDX: 78 vs 51 vs 24 days). Conclusions: We have identified a potentially novel strategy to enhance CAR-T cell persistence and efficacy in AML by counteracting a leukemia-induced,microRNA-deficiency mediated mechanism of immune suppression. View Publication

Aggregated α-synuclein (αSyn) is a pathological hallmark of Parkinson’s disease (PD),yet other protein aggregates,including tau,are commonly observed in PD brains. This suggests that PD is not solely a synucleinopathy but may involve multiple,coexisting proteinopathies. Mutations in LRRK2,particularly the G2019S (GS),are the most common cause of familial PD. LRRK2-PD has been associated with both αSyn and tau pathology; however the mechanistic links between LRRK2 dysfunction and protein aggregation remain incompletely defined. Here we opted to investigate whether LRRK2 contributes to αSyn and tau pathology through common molecular pathways or via distinct cellular mechanisms. Viral vector-mediated αSyn overexpression in GS LRRK2 knock-in mice led to enhanced dopaminergic neurodegeneration,increased phosphorylated αSyn levels,pronounced neuroinflammation,and accumulation of lysosomal proteins,suggesting impaired αSyn clearance and immune activation as key drivers. Human iPSC-derived dopaminergic neurons from GS LRRK2 PD patients mirrored these findings. In contrast viral vector-mediated overexpression of tau in GS LRRK2 knock-in mice promoted tau phosphorylation but did not significantly affect neuroinflammation,lysosomal markers,or neurodegeneration,indicating a primarily cell-autonomous mechanism. Our results reveal a mechanistic divergence in how GS LRRK2 impacts αSyn and tau pathologies,supporting the notion that LRRK2 kinase activity contributes to PD pathogenesis through different pathways,thereby highlighting its potential as a therapeutic target in both familial and sporadic PD. View Publication