技术资料

OBJECTIVES: Our objective was to develop and assess a novel endogenous progenitor cell (EPC) assay based on aldehyde dehydrogenase (ALDH) activity,and to define the relationship of ALDH-bright (ALDH(br)) cells with previously defined EPCs,patient age,and extent of coronary artery disease. BACKGROUND: Accurate assessment of circulating EPCs is of significant interest,yet current assays have limitations. Progenitor cells display high levels of ALDH activity. An assay based on ALDH activity may offer a simple means for enumerating EPCs. METHODS: We simultaneously determined the numbers of EPCs based on ALDH activity and cell surface expression of CD133,CD34,and vascular endothelial growth factor receptor-2 in 110 patients undergoing cardiac catheterization. We assessed the reproducibility of these estimates,correlation among EPC assays,and the association of ALDH(br) numbers with age and disease severity. RESULTS: Aldehyde dehydrogenase-bright cells were easily identified in nonmobilized peripheral blood with median and mean frequencies of 0.041% and 0.074%,respectively. Aldehyde dehydrogenase-bright cells expressed CD34 or CD133 cell surface markers (57.0% and 27.1%,respectively),correlated closely with CD133+CD34+ cells (r = 0.72; p textless 0.001),and differentiated into endothelial cells with greater efficiency than CD133+CD34+ cells. Aldehyde dehydrogenase-bright cell numbers were inversely associated with patient age and coronary disease severity. CONCLUSIONS: Aldehyde dehydrogenase activity represents a novel simplified method for quantifying EPCs. The correlation of ALDH(br) cells with clinical factors and outcomes warrants further study. View Publication

The enumeration of circulating tumor cells has long been regarded as an attractive diagnostic tool,as circulating tumor cells are thought to reflect aggressiveness of the tumor and may assist in therapeutic decisions in patients with solid malignancies. However,implementation of this assay into clinical routine has been cumbersome,as a validated test was not available until recently. Circulating tumor cells are rare events which can be detected specifically only by using a combination of surface and intracellular markers,and only recently a number of technical advances have made their reliable detection possible. Most of these new techniques rely on a combination of an enrichment and a detection step. This review addresses the assays that have been described so far in the literature,including the enrichment and detection steps and the markers used in these assays. We have focused on breast cancer as most clinical studies on CTC detection so far have been done in these patients. View Publication

Comprehensive in vitro and in vivo studies comparing EpCAM-based methods with other cytometric CTC enrichment technologies in metastatic colorectal cancer (mCRC) patients are lacking. We compare four manual cytometric methods to detect CTCs in vitro and in mCRC patients. The EpCAM-based technology,MACS HEA MicroBeads((R)),showed a significant better tumor cell recovery rate compared to other cytometric methods (p-valuetextless0.0001). CTCs of 38 mCRC patients were enriched with MACS HEA MicroBeads(R). Progression-free survival did significantly differ between mCRC patients without detectable and with textgreateror= 1 CTCs (p=0.007). CTC enrichment with EpCAM coupled antibodies is superior to other cytometric methods and is a feasible method for CTC detection in mCRC patients. View Publication

Sepsis represents uncontrolled inflammation due to an infection. Cold-inducible RNA-binding protein (CIRP) is a stress-induced damage-associated molecular pattern (DAMP). A subset of neutrophils expressing ICAM-1+ neutrophils was previously shown to produce high levels of reactive oxygen species. The role of CIRP for the development and function of ICAM-1+ neutrophils during sepsis is unknown. We hypothesize that CIRP induces ICAM-1 expression in neutrophils causing injury to the lungs during sepsis. Using a mouse model of cecal ligation and puncture (CLP)-induced sepsis,we found increased expression of CIRP and higher frequencies and numbers of ICAM-1+ neutrophils in the lungs. Conversely,the CIRP-/- mice showed significant inhibition in the frequencies and numbers of ICAM-1+ neutrophils in the lungs compared to wild-type (WT) mice in sepsis. In vitro treatment of bone marrow-derived neutrophils (BMDN) with recombinant murine CIRP (rmCIRP) significantly increased ICAM-1+ phenotype in a time- and dose-dependent manner. The effect of rmCIRP on increasing frequencies of ICAM-1+ neutrophils was significantly attenuated in BMDN treated with anti-TLR4 Ab or NF-κB inhibitor compared,respectively,with BMDN treated with isotype IgG or DMSO. The frequencies of iNOS producing and neutrophil extracellular traps (NETs) forming phenotypes in rmCIRP-treated ICAM-1+ BMDN were significantly higher than those in ICAM-1- BMDN. Following sepsis the ICAM-1+ neutrophils in the lungs showed significantly higher levels of iNOS and NETs compared to ICAM-1- neutrophils. We further revealed that ICAM-1 and NETs were co-localized in the neutrophils treated with rmCIRP. CIRP-/- mice showed significant improvement in their survival outcome (78% survival) over that of WT mice (48% survival) in sepsis. Thus,CIRP could be a novel therapeutic target for regulating iNOS producing and NETs forming ICAM-1+ neutrophils in the lungs during sepsis. View Publication

Vascular-deposited IgG immune complexes promote neutrophil recruitment,but how this process is regulated is still unclear. Here we show that the CD18 integrin Mac-1,in its bent state,interacts with the IgG receptor Fc$\gamma$RIIA in cis to reduce the affinity of Fc$\gamma$RIIA for IgG and inhibit Fc$\gamma$RIIA-mediated neutrophil recruitment under flow. The Mac-1 rs1143679 lupus-risk variant reverses Mac-1 inhibition of Fc$\gamma$RIIA,as does a Mac-1 ligand and a mutation in Mac-1's ligand binding $\alpha$I-domain. Sialylated complex glycans on Fc$\gamma$RIIA interact with the $\alpha$I-domain via divalent cations,and this interaction is required for Fc$\gamma$RIIA inhibition by Mac-1. Human neutrophils deficient in CD18 integrins exhibit augmented Fc$\gamma$RIIA-dependent recruitment to IgG-coated endothelium. In mice,CD18 integrins on neutrophils dampen IgG-mediated neutrophil accumulation in the kidney. In summary,cis interaction between sialylated Fc$\gamma$RIIA and the $\alpha$I-domain of Mac-1 alters the threshold for IgG-mediated neutrophil recruitment. A disruption of this interaction may increase neutrophil influx in autoimmune diseases. View Publication

Comparative genomics has revealed the rapid expansion of multiple gene families involved in immunity. Members within each gene family often evolved distinct roles in immunity. However,less is known about the evolution of their epigenome and cis-regulation. Here we systematically profile the epigenome of the recently expanded murine Ly49 gene family that mainly encode either inhibitory or activating surface receptors on natural killer cells. We identify a set of cis-regulatory elements (CREs) for activating Ly49 genes. In addition,we show that in mice,inhibitory and activating Ly49 genes are regulated by two separate sets of proximal CREs,likely resulting from lineage-specific losses of CRE activity. Furthermore,we find that some Ly49 genes are cross-regulated by the CREs of other Ly49 genes,suggesting that the Ly49 family has begun to evolve a concerted cis-regulatory mechanism. Collectively,we demonstrate the different modes of cis-regulatory evolution for a rapidly expanding gene family. The Ly49 gene family mainly encodes inhibitory or activating surface receptors on natural killer cells. Here the authors show that in mice,inhibitory and activating Ly49 genes are regulated by two distinct sets of cis-regulatory elements,and that different Ly49 genes can be cross-regulated. View Publication

Coronary artery disease (CAD) is linked to atherosclerosis plaque formation. In pro-inflammatory conditions,human Natural Killer (NK) cell frequencies in blood or plaque decrease; however,NK cells are underexplored in CAD pathogenesis,inflammatory mechanisms,and CAD comorbidities,such as human cytomegalovirus (HCMV) infection and diabetes. Analysis of PBMC CITE-seq data from sixty-one CAD patients revealed higher blood NK cell SPON2 expression in CAD patients with higher stenosis severity. Conversely,NK cell SPON2 expression was lower in pro-inflammatory atherosclerosis plaque tissue with an enriched adaptive NK cell gene signature. In CAD patients with higher stenosis severity,peripheral blood NK cell SPON2 expression was lower in patients with high HCMV-induced adaptive NK cell frequencies and corresponded to lower PBMC TGFβ transcript expression with dependency on diabetes status. These results suggest that high NK cell SPON2 expression is linked to atherosclerosis pro-homeostatic status and may have diagnostic and prognostic implications in cardiovascular disease. View Publication

The regulatory pathways necessary for the maintenance of adult hematopoietic stem cells (HSCs) remain poorly defined. By using loss-of-function approaches,we report a selective and cell-autonomous requirement for the p300/CBP-binding transcriptional coactivator Cited2 in adult HSC maintenance. Conditional deletion of Cited2 in the adult mouse results in loss of HSCs causing multilineage bone marrow failure and increased lethality. In contrast,conditional ablation of Cited2 after lineage specification in lymphoid and myeloid lineages has no impact on the maintenance of these lineages. Additional deletion of Ink4a/Arf (encoding p16(Ink4a) and p19(Arf)) or Trp53 (encoding p53,a downstream target of p19(Arf)) in a Cited2-deficient background restores HSC functionality and rescues mice from bone marrow failure. Furthermore,we show that the critical role of Cited2 in primitive hematopoietic cells is conserved in humans. Taken together,our studies provide genetic evidence that Cited2 selectively maintains adult HSC functions,at least in part,via Ink4a/Arf and Trp53. View Publication

Cited2 (cAMP-responsive elementbinding protein [CBP]/p300-interacting transactivators with glutamic acid [E] and aspartic acid [D]-rich tail 2) is a newly identified transcriptional modulator. Knockout of the Cited2 gene results in embryonic lethality with embryos manifesting heart and neural tube defects. Cited2-/- fetal liver displayed significant reduction in the numbers of Lin(-)c-Kit+Sca-1+ cells,Lin(-)c-Kit+ cells,and progenitor cells of different lineages. Fetal liver cells from Cited2-/- embryos gave rise to markedly reduced number of colonies in the colony-forming unit assay. Primary and secondary transplantation studies showed significantly compromised reconstitution of T-lymphoid,B-lymphoid,and myeloid lineages in mice that received a transplant of Cited2-/- fetal liver cells. Competitive reconstitution experiments further showed that fetal liver hematopoietic stem cell (HSC) function is severely impaired due to Cited2 deficiency. Microarray analysis showed decreased expression of Wnt5a and a panel of myeloid molecular markers such as PRTN3,MPO,Neutrophil elastase,Cathepsin G,and Eosinophil peroxidase in Cited2-/- fetal livers. Decreased expression of Bmi-1,Notch1,LEF-1,Mcl-1,and GATA2 was also observed in Cited2-/- Lin(-)c-Kit+ cells. The present study uncovers for the first time a novel role of Cited2 in the maintenance of hematopoietic homeostasis during embryogenesis and thus provides new insights into the molecular regulation of hematopoietic development. View Publication

Citron Kinase (CITK) is a protein encoded by the CIT gene,whose pathogenic variants underlie microcephalic phenotypes that characterize MCPH17 syndrome. In neural progenitors,CITK loss leads to microtubule instability,resulting in mitotic spindle positioning defects,cytokinesis failure,and accumulation of DNA double strand breaks (DSBs),ultimately resulting in TP53-dependent senescence and apoptosis. Although DNA damage accumulation has been associated with impaired homologous recombination (HR),the role of CITK in this process and whether microtubule dynamics are involved is still unknown. In this report we show that CITK is required for proper BRCA1 localization at sites of DNA DSBs. We found that CITK’s scaffolding,rather than its catalytic activity,is necessary for maintaining BRCA1 interphase levels in progenitor cells during neurodevelopment. CITK regulates the nuclear levels of HDAC6,a modulator of both microtubule stability and DNA damage repair. Targeting HDAC6 in CITK-deficient cells increases microtubule stability and recovers BRCA1 localization defects and DNA damage levels to that detected in controls. In addition,the CIT-HDAC6 axis is functionally relevant in a MCPH17 zebrafish model,as HDAC6 targeting recovers the head size phenotype produced by interfering with the CIT orthologue gene. These data provide novel insights into the functional interplay between HR and microtubule dynamics and into the pathogenesis of CITK based MCPH17,which may be relevant for development of therapeutic strategies. View Publication

A number of genes regulate regeneration of peripheral axons,but their ability to drive axon growth and regeneration in the central nervous system (CNS) remains largely untested. To address this question we overexpressed eight transcription factors and one small GTPase alone and in pairwise combinations to test whether combinatorial overexpression would have a synergistic impact on CNS neuron neurite growth. The Jun oncogene/signal transducer and activator of transcription 6 (JUN/STAT6) combination increased neurite growth in dissociated cortical neurons and in injured cortical slices. In injured cortical slices,JUN overexpression increased axon growth to a similar extent as JUN and STAT6 together. Interestingly,JUN overexpression was not associated with increased growth associated protein 43 (GAP43) or integrin alpha 7 (ITGA7) expression,though these are predicted transcriptional targets. This study demonstrates that JUN overexpression in cortical neurons stimulates axon growth,but does so independently of changes in expression of genes thought to be critical for JUNs effects on axon growth. We conclude that JUN activity underlies this CNS axonal growth response,and that it is mechanistically distinct from peripheral regeneration responses,in which increases in JUN expression coincide with increases in GAP43 expression. View Publication

Natural killer (NK) cells,which are key components of the innate immune response,are crucial for ensuring the efficacy of vaccines as they rapidly eliminate infected cells and enhance the adaptive immune response,ensuring robust and lasting protection. In this report,we investigated the effect of Cladophora wrightiana var. minor (CW) extract,a marine alga,in activating NK cells,as an adjuvant to inactivated A/Puerto Rico/8/34 H1N1 influenza vaccine (iPR8). In vitro,CW extract significantly enhanced the level of activation markers CD69 and CD107a on NK cells and triggered intracellular secretion of interferon gamma (IFN‐γ) and granzyme B (GrB),indicating effective NK cell stimulation and cytotoxic function. In vivo,CW extract promoted substantial NK cell recruitment and activation,resulting in higher NK cell populations and elevated post‐immunization levels of activation markers. Additionally,CW extract increased IFN‐γ and GrB production in CD8+ T cells,highlighting its broader impact on the immune response. We also found direct evidence that CW‐activated NK cells and dendritic cells (DCs) interacted with and induced the activation of immature DCs and resting NK cells,respectively. These findings suggest that CW extract is a promising adjuvant for nasal vaccines,enhancing cellular immunity by activating NK cells and supporting interactions with DCs and CD8+ T cells. Cladophora wrightiana var. minor (CW) extract,administered as an adjuvant with inactivated influenza virus (iPR8),stimulates both innate and adaptive immune responses. CW enhances NK cell activation,cytotoxic function,and reciprocal crosstalk with dendritic cells,while also promoting CD8+ T cell responses and antigen‐specific IgG production. These findings support CW as a potent nasal vaccine adjuvant capable of boosting protective immunity. https://app.biorender.com/illustrations/6893f7d09e3fc89e9d953f76?slideId=2a6a42b6‐a3d9‐400a‐b839‐fa297b3108c5. View Publication