Inflammatory bowel diseases(IBD), which comprise Crohn's disease and ulcerative colitis, are chronic intestinal disorders with an increased prevalence and incidence over the last decade in many different regions o...Inflammatory bowel diseases(IBD), which comprise Crohn's disease and ulcerative colitis, are chronic intestinal disorders with an increased prevalence and incidence over the last decade in many different regions over the world. The etiology of IBD is still not well defined, but evidence suggest that it results from per-turbation of the homeostasis between the intestinal microbiota and the mucosal immune system, with the involvement of both genetic and environmental factors. Genome wide association studies, which involve large-scale genome-wide screening of potential polymorphism, have identified several mutations associated with IBD. Among them, Card9, a gene encoding an adapter molecule involved in innate immune response to fungi(via type C-lectin sensing) through the activation of IL-22 signaling pathway, has been identified as one IBD susceptible genes. Dietary compounds, which represent a source of energy and metabolites for gut bacteria, are also appreciated to be important actors in the etiology of IBD, for example by altering gut microbiota composition and by regulating the generation of short chain fatty acids. A noteworthy study published in the June 2016 issue of Nature Medicine by Lamas and colleagues investigates the interaction between Card9 and the gut microbiota in the generation of the microbiota-derived tryptophan metabolite. This study highlights the role of tryptophan in dampening intestinal inflammation in susceptible hosts.展开更多
Background:Alterations in ambient temperature have been associated with multiple detrimental effects on broilers such as intestinal barrier disruption and dysbiosis resulting in systemic inflammation.Inflammation and ...Background:Alterations in ambient temperature have been associated with multiple detrimental effects on broilers such as intestinal barrier disruption and dysbiosis resulting in systemic inflammation.Inflammation and 25-hydroxycholecalciferol(25-OH-D_(3))have shown to play a negative and positive role,respectively,in the regulation of bone mass.Hence the potential of 25-OH-D_(3)in alleviating heat induced bone alterations and its mechanisms was studied.Results:Heat stress(HS)directly induced a decrease in tibia material properties and bone mass,as demonstrated by lower mineral content,and HS caused a notable increase in intestinal permeability.Treatment with dietary 25-OH-D_(3)reversed the HS-induced bone loss and barrier leak.Broilers suffering from HS exhibited dysbiosis and increased expression of inflammatory cytokines in the ileum and bone marrow,as well as increased osteoclast number and activity.The changes were prevented by dietary 25-OH-D_(3)administration.Specifically,dietary 25-OH-D_(3)addition decreased abundance of B-and T-cells in blood,and the expression of inflammatory cytokines,especially TNF-α,in both the ileum and bone marrow,but did not alter the diversity and population or composition of major bacterial phyla.With regard to bone remodeling,dietary 25-OH-D_(3)supplementation was linked to a decrease in serum C-terminal cross-linked telopeptide of type I collagen reflecting bone resorption and a concomitant decrement in osteoclast-specific marker genes expression(e.g.cathepsin K),whereas it did not apparently change serum bone formation markers during HS.Conclusions:These data underscore the damage of HS to intestinal integrity and bone health,as well as that dietary 25-OH-D_(3)supplementation was identified as a potential therapy for preventing these adverse effects.展开更多
Hepatic encephalopathy,defined as neuropsychiatric dysfunction secondary to liver disease,is a frequent decompensating event in cirrhosis.Its clinical impact is highlighted by a notable increase in patient mortality r...Hepatic encephalopathy,defined as neuropsychiatric dysfunction secondary to liver disease,is a frequent decompensating event in cirrhosis.Its clinical impact is highlighted by a notable increase in patient mortality rates and a concomitant reduction in overall quality of life.Systemically,liver disease,liver function failure,portosystemic shunting,and associated multi-organ dysfunction result in the increase of disease-causing neurotoxins in the circulation,which impairs cerebral homeostasis.Key circulating neurotoxins are ammonia and inflammatory mediators.In the brain,pathophysiology is less well understood,but is thought to be driven by glial cell dysfunction.Astrocytes are the only brain resident cells that have ammonia-metabolizing machinery and are therefore putatively most susceptible to ammonia elevation.Based on a large body of mostly in vitro evidence,ammonia-induced cellular and molecular disturbances include astrocyte swelling and oxidative stress.Microglia,the brain resident macrophages,have been linked to the translation of systemic inflammation to the brain microenvironment.Recent evidence from animal studies has provided novel insights into old and new downstream effects of astrocyte and microglial dysfunction such as toxin clearance disruption and myeloid cell attraction to the central nervous system parenchyma.Furthermore,state of the art research increasingly implicates neuronal dysfunction and possibly even irreversible neuronal cell death.Cell-type specific investigation in animal models highlights the need for critical revision of the contribution of astrocytes and microglia to well-established and novel cellular and molecular alterations in hepatic encephalopathy.In this review,we therefore give a current and comprehensive overview of causes,features,and consequences of astrocyte and microglial dysfunction in hepatic encephalopathy,including areas of interest for future investigation.展开更多
Background Heat stress(HS) incidence is associated with the accumulation of reactive substances, which might be associated with bone loss. N-Acetylcysteine(NAC) exhibits strong antioxidants due to its sulfhydryl group...Background Heat stress(HS) incidence is associated with the accumulation of reactive substances, which might be associated with bone loss. N-Acetylcysteine(NAC) exhibits strong antioxidants due to its sulfhydryl group and being as the precursor for endogenous glutathione synthesis. Therefore, interplay between oxidative stress and bone turnover of broilers and the effects of dietary NAC inclusion on antioxidant capability and “gut-bone” axis were evaluated during chronic HS.Results Implementing cyclic chronic HS(34 ℃ for 7 h/d) evoked reactive oxygen species excessive production and oxidant stress, which was accompanied by compromised tibia mass. The RNA-seq of proximal tibia also revealed the enrichment of oxidation–reduction process and inflammatory outbursts during HS. Although no notable alterations in the growth performance and cecal microbiota were found, the diet contained 2 g/kg NAC enhanced the antioxidant capability of heat-stressed broiler chickens by upregulating the expression of Nrf2 in the ileum, tibia, and bone marrow. Simultaneously, NAC tended to hinder NF-κB pathway activation and decreased the m RNA levels of the proinflammatory cytokines in both the ileum and bone marrow. As a result, NAC suppressed osteoclastogenesis and osteoclast activity, thereby increasing osteocyte-related gene expression. Furthermore, the inclusion of NAC tended to increase the ash content and density of the whole tibia, as well as improve cortical thickness and bone volume of the diaphysis.Conclusions These findings HS-mediated outburst of oxidant stress accelerates bone resorption and negatively regulates the bone quality of tibia, which is inhibited by NAC in broilers.展开更多
BACKGROUND Chronic abdominal pain is the most common cause for gastroenterology consultation and is frequently associated with functional gastrointestinal disorders including irritable bowel syndrome and inflammatory ...BACKGROUND Chronic abdominal pain is the most common cause for gastroenterology consultation and is frequently associated with functional gastrointestinal disorders including irritable bowel syndrome and inflammatory bowel disease. These disorders present similar brain/gut/microbiota trialogue alterations, associated with abnormal intestinal permeability, intestinal dysbiosis and colonic hypersensitivity(CHS). Intestinal dysbiosis can alter colon homeostasis leading to abnormal activation of the innate immunity that promotes CHS, perhaps involving the toll-like receptors(TLRs), which play a central role in innate immunity.AIM To understand the mechanisms between early life event paradigm on intestinal permeability, fecal microbiota composition and CHS development in mice with TLRs expression in colonocytes.METHODS Maternal separation model(NMS) CHS model, which mimics deleterious events in childhood that can induce a wide range of chronic disorders during adulthood were used. Colonic sensitivity of NMS mice was evaluated by colorectal distension(CRD) coupled with intracolonic pressure variation(IPV) measurement. Fecal microbiota composition was analyzed by 16S rRNA sequencing from weaning to CRD periods. TLR mRNA expression was evaluated in colonocytes.Additionally, the effect of acute intrarectal instillation of the TLR5 agonist flagellin(FliC) on CHS in adult naive wildtype mice was analyzed.RESULTS Around 50% of NMS mice exhibited increased intestinal permeability and CHS associated with intestinal dysbiosis, characterized by a significant decrease of species richness, an alteration of the core fecal microbiota and a specific increased relative abundance of flagellated bacteria. Only TLR5mRNA expression was increased in colonocytes of NMS mice with CHS. Acute intrarectal instillation of FliC induced transient increase of IPV, reflecting transient CHS appearance.CONCLUSION Altogether, these data suggest a pathophysiological continuum between intestinal dysbiosis and CHS, with a role for TLR5.展开更多
Due to the aging of the population and despite the enormous scientific effort,Alzheimer's disease remains one of the biggest medical and pharmaceutical challenges in current medicine.Novel insights highlight the i...Due to the aging of the population and despite the enormous scientific effort,Alzheimer's disease remains one of the biggest medical and pharmaceutical challenges in current medicine.Novel insights highlight the importance of neuroinflammation as an undeniable player in the onset and progression of Alzheimer's disease.Tumor necrosis factor is a master inflammatory cytokine that signals via tumor necrosis factor receptor 1 and tumor necrosis factor receptor 2,but that also regulates several brain functions in health and disease.However,clinical trials investigating drugs that interfere with the tumor necrosis factor pathway in Alzheimer's disease led to inconclusive results,partially because not only the pro-inflammatory tumor necrosis factor/tumor necrosis factor receptor 1,but also the beneficial tumor necrosis factor/tumor necrosis factor receptor 2 signaling was antagonized in these trials.We recently found that tumor necrosis factor is the main upregulated cytokine in the choroid plexus of Alzheimer's disease patients,signaling via tumor necrosis factor receptor 1.In agreement with this,choroidal tumor necrosis factor/tumor necrosis factor receptor 1 signaling was also upregulated in different Alzheimer's disease mouse models.Interestingly,both genetic and nanobody-based pharmacological blockage of tumor necrosis factor receptor 1 signaling was accompanied by favorable effects on Alzheimer's disease-associated inflammation,choroidal morphology and cognitive functioning.Here,we briefly summarize the detrimental effects that can be mediated by tumor necrosis factor/tumor necrosis factor receptor 1 signaling in(early) Alzheimer's disease,and the consequences this might have on the disease progression.As the main hypothesis in Alzheimer's disease clinical trials is still based on the amyloid beta-cascade,the importance of Alzheimer's disease-associated neuroinflammation urge the development of novel therapeutic strategies that might be effective in the early stages of Alzheimer's disease and prevent the irreversible neurodegeneration and resulting memory decline.展开更多
B lymphoma Moloney murine leukemia virus insertion region 1 (BMI1), a core member of polycomb repressive complex 1 (PRC1), has been intensely investigated in the field of cancer epigenetics for decades. Widely known a...B lymphoma Moloney murine leukemia virus insertion region 1 (BMI1), a core member of polycomb repressive complex 1 (PRC1), has been intensely investigated in the field of cancer epigenetics for decades. Widely known as a critical regulator in cellular physiology, BMI1 is essential in self-renewal and differentiation in different lineages of stem cells. BMI1 also plays a significant role in cancer etiology for its involvement in pathological progress such as epithelial–mesenchymal transition (EMT) and cancer stem cell maintenance, propagation, and differentiation. Importantly, overexpression of BMI1 is predictive for drug resistance, tumor recurrence, and eventual therapy failure of various cancer subtypes, which renders the pharmacological targeting at BMI1 as a novel and promising therapeutic approach. The study on prostate cancer, a prevalent hormone-related cancer among men, has promoted enormous research advancements in cancer genetics and epigenetics. This review summarizes the role of BMI1 as an oncogenic and epigenetic regulator in tumor initiation, progression, and relapse of prostate cancer.展开更多
Type 2^(high) asthma,which accounts for the majority of asthma cases,is driven by Th2 cells that produce cytokines such as IL-4,IL-5,and IL-13.These cytokines promote several features of the disease,including eosinoph...Type 2^(high) asthma,which accounts for the majority of asthma cases,is driven by Th2 cells that produce cytokines such as IL-4,IL-5,and IL-13.These cytokines promote several features of the disease,including eosinophilia,IgE production,bronchial hyperresponsiveness(BHR),mucus hypersecretion,and susceptibility to exacerbations.In contrast,type 2^(low) asthma is characterized by the presence of neutrophils and reduced responsiveness to corticosteroids.In recent years,advances in our understanding of the distinct mechanisms at play in each asthma endotype have paved the way for the development of targeted therapies tailored to specific patient profiles.In this review,we first explore the underlying immunological mechanisms of various asthma endotypes.We also provide an overview of the different types of immunotherapies currently available to asthmatic patients and their clinical efficacy.Finally,we highlight emerging therapeutic strategies that hold promise for improving asthma management in the future.展开更多
Pneumonia, the most typical and frequent lower respiratory tract infection （LRTI）, is a leading cause of health problems in the United States. Bacteria represent the most prevailing cause of pneumonia in both childr...Pneumonia, the most typical and frequent lower respiratory tract infection （LRTI）, is a leading cause of health problems in the United States. Bacteria represent the most prevailing cause of pneumonia in both children and adults. Although pneumonia with a single bacterial infection is common, a significant portion of patients with pneumonia is polymicrobial. This infection is often complexed with other physiological factors such as cytokines and growth factors. Nontypeable Haemophilus influenzae （NTHi） is the most frequently recovered Gram-negative bacterial pathogen in the respiratory system and induces strong inflammatory responses. NTHi also synergizes with other respiratory pathogens, such as Streptococcus pneumoniae and respiratory viruses and pro-inflammatory cytokines, such as tumor necrosis factor-alpha （TNF-α）. It is noteworthy that NTHi not only synergizes with growth factors such as transforming growth factor-beta （TGF-β）, but also utilizes growth factor receptors such as TGF-β receptor and epidermal growth factor receptor （EGFR）, to enhance inflammatory responses. Although appropriate inflammation is a protective response against invading pathogens, an uncontrolled inflammatory response is often detrimental to the host. Thus, inflammation must be tightly regulated. The human immune system has evolved strategies for controlling overactive inflammatory response. One such important mechanism is via regulation of negative feedback regulators for inflammation. CYLD, a multifunctional deubiquitinase, was originally reported as a tumor suppressor, but was recently identified as a negative regulator for nuclear factor-kappa B （NF-κB） signaling. It is induced by NTHi and TNF-α via a NF-κB-dependent mechanism, thereby serving as an inducible negative feedback regulator for tightly controlling inflammation in NTHi infection.展开更多
Cytotoxic T lymphocytes （CTLs） and natural killer （NK） cells contribute to the body＇s immune defenses. Current chimeric antigen receptor （CAR）-modified T cell immunotherapy shows strong promise for treating var...Cytotoxic T lymphocytes （CTLs） and natural killer （NK） cells contribute to the body＇s immune defenses. Current chimeric antigen receptor （CAR）-modified T cell immunotherapy shows strong promise for treating var- ious cancers and infectious diseases. Although CAR- modified NK cell immunotherapy is rapidly gaining attention, its clinical applications are mainly focused on preclinical investigations using the NK92 cell line. Despite recent advances in CAR-modified T cell immunotherapy, cost and severe toxicity have hindered its widespread use. To alleviate these disadvantages of CAR-modified T cell immunotherapy, additional cyto- toxic cell-mediated immunotherapies are urgently nee- ded. The unique biology of NK cells allows them to serve as a safe, effective, alternative immunotherapeutic strategy to CAR-modified T cells in the clinic. While the fundamental mechanisms underlying the cytotoxicity and side effects of CAR-modified T and NK cell immunotherapies remain poorly understood, the for- mation of the immunological synapse （IS） between CAR- modified T or NK cells and their susceptible target cells is known to be essential. The role of the IS in CAR T and NK cell immunotherapies will allow scientists to harness the power of CAR-modified T and NK cells to treat can- cer and infectious diseases. In this review, we highlight the potential applications of CAR-modified NK cells to treat cancer and human immunodeficiency virus （HIV）, and discuss the challenges and possible future directions of CAR-modified NK cell immunotherapy, as well as the importance of understanding the molecular mechanisms of CAR-modified T cell- or NK cell-medi- ated cytotoxicity and side effects, with a focus on the CAR-modified NK cell IS.展开更多
Although the plant kingdom provides an enormous diversity of metabolites with potentially beneficial applications for humankind,a large fraction of these metabolites and their biosynthetic pathways remain unknown.Reso...Although the plant kingdom provides an enormous diversity of metabolites with potentially beneficial applications for humankind,a large fraction of these metabolites and their biosynthetic pathways remain unknown.Resolving metabolite structures and their biosynthetic pathways is key to gaining biological understanding andto allow metabolic engineering.In orderto retrieve novel biosynthetic genes involved in specialized metabolism,we developed a novel untargeted method designated as qualitative trait GWAs(QT-GWAS)that subjects qualitative metabolic traits to a genome-wide association study,while the conventional metabolite GWAS(mGWAS)mainly considers the quantitative variation of metabolites.As a proof of the validity of QT-GWAS,23 and 15of the retrieved associations identified in Arabidopsis thaliana by QTGWAS and mGWAS,respectively,were supported by previous research.Furthermore,seven genemetabolite associations retrieved by QT-GWAS were confirmed in this study through reverse genetics combined with metabolomics and/or in vitro enzyme assays.As such,we established that CYTOCHROME P450706A5(CYP706A5)is involved in the biosynthesis of chroman derivatives,UDP-GLYCOSYLTRANSFERASE 76C3(UGT76C3)is able tohexosylate guanine in vitro and in planta,and SULFOTRANSFERASE 202B1(SULT202B1)catalyzes the sulfation of neolignans in vitro.Collectively,our study demonstrates that the untargeted QT-GWAS method can retrieve valid gene-metabolite associations at the level of enzyme-encoding genes,even new associations that cannot be found by the conventional mGwAs,providing a new approach for dissecting qualitative metabolic traits.展开更多
Hepatic ischemia–reperfusion injury(HIRI)is an important cause of liver injury following liver transplantation and major resections,and neutrophils are the key effector cells in HIRI.Double-negative T regulatory cell...Hepatic ischemia–reperfusion injury(HIRI)is an important cause of liver injury following liver transplantation and major resections,and neutrophils are the key effector cells in HIRI.Double-negative T regulatory cells(DNT)are increasingly recognized as having critical regulatory functions in the immune system.Whether DNT expresses distinct immunoregulatory mechanisms to modulate neutrophils,as in HIRI,remains largely unknown.In this study,we found that murine and human DNT highly expressed CD39that protected DNT from extracellular ATP-induced apoptosis and generated adenosine in tandem with CD73,to induce high levels of neutrophil apoptosis.Furthermore,extracellular adenosine enhanced DNT survival and suppressive function by upregulating survivin and NKG2D expression via the A2AR/pAKT/FOXO1 signaling pathway.Adoptive transfer of DNT ameliorated HIRI in mice through the inhibition of neutrophils in a CD39-dependent manner.Lastly,the adoptive transfer of A2ar^(-/-)DNT validated the importance of adenosine/A2AR signaling,in promoting DNT survival and immunomodulatory function to protect against HIRI in vivo.In conclusion,purinergic signaling is crucial for DNT homeostasis in HIRI.Augmentation of CD39 or activation of A2AR signaling in DNT may provide novel therapeutic strategies to target innate immune disorders.展开更多
The differentiation status of neuroblastoma （NB） strongly correlates with its clinical outcomes; however, the molecular mechanisms driving maintenance of sternness and differentiation remain poorly understood. Here,...The differentiation status of neuroblastoma （NB） strongly correlates with its clinical outcomes; however, the molecular mechanisms driving maintenance of sternness and differentiation remain poorly understood. Here, we show that plant homeodomain finger-containing protein 20 （PHF20） functions as a critical epigenetic regulator in sustaining stem cell-like phenotype of NB by using CRISPR/Casg-based targeted knockout （KO） for high-throughput screening of gene function in NB cell differentiation. The expression of PHF20 in NB was significantly associated with high aggressiveness of the tumor and poor outcomes for NB patients. Deletion of PHF20 inhibited NB cell proliferation, invasive migration, and stem ceU-Uke traits. Mechanistically, PHF20 interacts with poly（ADP-ribose） polymerase 1 （PARP1） and directly binds to promoter regions of octamer-binding transcription factor 4 （OCT4） and sex determining region Y-box 2 （SOX2） to modulate a histone mark associated with active transcription, trimethylation of lysine 4 on histone H3 protein subunit （H3K4me3）. Overexpression of OCT4 and SOX2 restored growth and progression of PHF20 KO tumor cells. Consistently, OCT4 and SOX2 protein levels in clinical NB specimens were positively correlated with PHF20 expression. Our results establish PHF20 as a key driver of NB stem cell-like properties and aggressive behaviors, with implications for prognosis and therapy.展开更多
Acute systemic inflammation critically alters the function of the immune system,often promoting myelopoiesis at the expense of lymphopoiesis.In the thymus,systemic inflammation results in acute thymic atrophy and,cons...Acute systemic inflammation critically alters the function of the immune system,often promoting myelopoiesis at the expense of lymphopoiesis.In the thymus,systemic inflammation results in acute thymic atrophy and,consequently,impaired T-lymphopoiesis.The mechanism by which systemic inflammation impacts the thymus beyond suppressing T-cell development is still unclear.Here,we describe how the synergism between TL1A and IL-18 suppresses T-lymphopoiesis to promote thymic myelopoiesis.The protein levels of these two cytokines were elevated in the thymus during viral-induced thymus atrophy infection with murine cytomegalovirus(MCMV)or pneumonia virus of mice(PVM).In vivo administration of TL1A and IL-18 induced acute thymic atrophy,while thymic neutrophils expanded.Fate mapping with Ms4a3-Cre mice demonstrated that thymic neutrophils emerge from thymic granulocyte-monocyte progenitors(GMPs),while Rag1-Cre fate mapping revealed a common developmental path with lymphocytes.These effects could be modeled ex vivo using neonatal thymic organ cultures(NTOCs),where TL1A and IL-18 synergistically enhanced neutrophil production and egress.NOTCH blockade by the LY411575 inhibitor increased the number of neutrophils in the culture,indicating that NOTCH restricted steady-state thymic granulopoiesis.To promote myelopoiesis,TL1A,and IL-18 synergistically increased GM-CSF levels in the NTOC,which was mainly produced by thymic ILC1s.In support,TL1A-and IL-18-induced granulopoiesis was completely prevented in NTOCs derived from Csf2rb-/-mice and by GM-CSFR antibody blockade,revealing that GM-CSF is the essential factor driving thymic granulopoiesis.Taken together,our findings reveal that TL1A and IL-18 synergism induce acute thymus atrophy while promoting extramedullary thymic granulopoiesis in a NOTCH and GM-CSF-controlled manner.展开更多
Regulatory T （Treg） cells play a central role in regulating peripheral immune tolerance and preventing autoimmunity. Despite the extensive studies on the development of Treg cells, the molecular mechanisms that main...Regulatory T （Treg） cells play a central role in regulating peripheral immune tolerance and preventing autoimmunity. Despite the extensive studies on the development of Treg cells, the molecular mechanisms that maintain the population of committed Treg cells remain poorly understood. We show here that Treg-conditional ablation of the kinase TAK1 reduced the number of Treg cells in the peripheral lymphoid organs, causing abnormal activation of conventional T cells and autoimmune symptoms. Using an inducible gene knockout approach, we further demonstrate that TAK1 is crucial for the survival of Treg cells. Expression of a constitutively active IKB kinase partially restored the level of Treg cells in the TAKITreg-KO mice. These results suggest a crucial role for TAK1 for maintaining the survival of committed Treg cells under physiololzical conditions.展开更多
Human cells contain two types of adenosine deaminases(ADA)each with unique properties:ADA1,which is present in all cells where it modulates intracellular functions and extracellular signaling,and ADA2,which is secrete...Human cells contain two types of adenosine deaminases(ADA)each with unique properties:ADA1,which is present in all cells where it modulates intracellular functions and extracellular signaling,and ADA2,which is secreted by immune cells.The exact intracellular functions of ADA2 remain undetermined and less defined than those of ADA1.ADA2 has distinct characteristics,such as low adenosine affinity,heparin-binding ability,and putative lysosomal entry.Here,we confirm that ADA2 is a lysosomal protein that binds toll-like receptor 9(TLR9)agonists,specifically CpG oligodeoxynucleotides(CpG ODNs).We show that interferon-alpha(IFN-α)is secreted in response to TLR9 activation by CpG ODNs and natural DNA and markedly increases when ADA2 expression is downregulated in plasmacytoid dendritic cells(pDCs).Additionally,the pretreatment of pDCs with RNA further stimulates IFN-αsecretion by pDCs after activation with CpG ODNs.Our findings indicate that ADA2 regulates TLR9 responses to DNA in activated pDCs.In conclusion,decreasing ADA2 expression or blocking it with specific oligonucleotides can enhance IFN-αsecretion from pDCs,improving immune responses against intracellular infections and cancer.展开更多
Fluorescence microscopy is the method of choice for studying intracellular dynamics.However,its success depends on the.availability of specific and stable markers.A prominent example of markers that are rapidly gainin...Fluorescence microscopy is the method of choice for studying intracellular dynamics.However,its success depends on the.availability of specific and stable markers.A prominent example of markers that are rapidly gaining interest are nanobodies(Nbs.-15 kDa),which can be functionalized with bright and photostable organic fluorophores.Due to their relatively small size and high specificity,Nbs offer great potential for high-quality long-term subcellular imaging,but suffer from the fact that they cannot spontaneously cross the plasma membrane of live cells.We have recently discovered that laser-induced photoporation is well suited to deliver extrinsic labels to living cells without compromising their viability.Being a laser-based technology,it is readily compatible with light microscopy and the typical cell recipients used for that.Spurred by these promising initial results,we demonstrate here for the first time successful long-term imaging of specific subcellular structures with labeled nanobodies in living cells.We illustrate this using Nbs that target GFP/YFP-protein constructs accessible in the cytoplasm,actin-bundling protein Fascin,and the histone H2A/H2B heterodimers.With an efficiency of more than 80%labeled cells and minimal toxicity(-2%),photoporation proved to be an excellent intracellular delivery method for Nbs.Time-lapse microscopy revealed that cell division rate and migration remained unaffected,confirming excellent cell viability and functionality.We conclude that laser-induced photoporation labeled Nbs can be easily delivered into living cells,laying the foundation for further development of a broad range of Nbs with intracellular targets as a toolbox for long-term live-cell microscopy.展开更多
The imbalance between pathogenic and protective T cell subsets is a cardinal feature of autoimmune disorders such as multiple sclerosis(MS).Emerging evidence indicates that endogenous and dietary-induced changes in fa...The imbalance between pathogenic and protective T cell subsets is a cardinal feature of autoimmune disorders such as multiple sclerosis(MS).Emerging evidence indicates that endogenous and dietary-induced changes in fatty acid metabolism have a major impact on both T cell fate and autoimmunity.To date,however,the molecular mechanisms that underlie the impact of fatty acid metabolism on T cell physiology and autoimmunity remain poorly understood.Here,we report that stearoyl-CoA desaturase-1(SCD1),an enzyme essential for the desaturation of fatty acids and highly regulated by dietary factors,acts as an endogenous brake on regulatory T-cell(Treg)differentiation and augments autoimmunity in an animal model of MS in a T cell-dependent manner.Guided by RNA sequencing and lipidomics analysis,we found that the absence of Scd1 in T cells promotes the hydrolysis of triglycerides and phosphatidylcholine through adipose triglyceride lipase(ATGL).ATGL-dependent release of docosahexaenoic acid enhanced Treg differentiation by activating the nuclear receptor peroxisome proliferator-activated receptor gamma.Our findings identify fatty acid desaturation by SCD1 as an essential determinant of Treg differentiation and autoimmunity,with potentially broad implications for the development of novel therapeutic strategies and dietary interventions for autoimmune disorders such as MS.展开更多
After activation by antigen-presenting cells,naive,antigenspecific CD41 T cells differentiate into effector T cells.Two decades ago,Coffman and Mosman first discovered the heterogeneity of effector T cells,which were...After activation by antigen-presenting cells,naive,antigenspecific CD41 T cells differentiate into effector T cells.Two decades ago,Coffman and Mosman first discovered the heterogeneity of effector T cells,which were named as Th1 or Th2 cells.1 Th1 and Th2 cells are differentially induced and are involved in immunity against intracellular and extracellular pathogens,respectively,as well as immunopathologies such as autoimmunity and allergy.The Th1/Th2 dichotomy dominated the field of immune regulation until about 4 years ago when IL-17-expressing T cells were proposed to be a third lineage of helper T cells.展开更多
Mutations in tumors can create a state of increased cellular plasticity that promotes resistance to treatment. Thus, there is an urgent need to develop novel strategies for identifying key factors that regulate cellul...Mutations in tumors can create a state of increased cellular plasticity that promotes resistance to treatment. Thus, there is an urgent need to develop novel strategies for identifying key factors that regulate cellular plasticity in order to combat resistance to chemotherapy and radiation treatment. Here we report that prostate epithelial cell reprogramming could be exploited to identify key factors required for promoting prostate cancer tumorigenesis and cellular plasticity. Deletion of phosphatase and tensin homolog （Pten） and transforming growth factor-beta receptor type 2 （Tgfbr2） may increase prostate epithelial cell reprogramming efficiency in vitro and cause rapid tumor development and early mortality in vivo. Tgfbr2 ablation abolished TGF-β signaling but increased the bone morphogenetic protein （BMP） signaling pathway through the negative regulator Tmeff1. Furthermore, increased BMP signaling promotes expression of the tumor marker genes ID1, Oct4, Nanog, and Sox2; ID1/STAT3/NANOG expression was inversely correlated with patient survival. Thus, our findings provide information about the molecular mechanisms by which BMP signaling pathways render stemness capacity to prostate tumor cells.展开更多
基金Supported by National Institutes of Health(NIH),Nos.DK099071 and DK083890the Career Development Award from the Crohn’s and Colitis Foundation of America(CCFA)
文摘Inflammatory bowel diseases(IBD), which comprise Crohn's disease and ulcerative colitis, are chronic intestinal disorders with an increased prevalence and incidence over the last decade in many different regions over the world. The etiology of IBD is still not well defined, but evidence suggest that it results from per-turbation of the homeostasis between the intestinal microbiota and the mucosal immune system, with the involvement of both genetic and environmental factors. Genome wide association studies, which involve large-scale genome-wide screening of potential polymorphism, have identified several mutations associated with IBD. Among them, Card9, a gene encoding an adapter molecule involved in innate immune response to fungi(via type C-lectin sensing) through the activation of IL-22 signaling pathway, has been identified as one IBD susceptible genes. Dietary compounds, which represent a source of energy and metabolites for gut bacteria, are also appreciated to be important actors in the etiology of IBD, for example by altering gut microbiota composition and by regulating the generation of short chain fatty acids. A noteworthy study published in the June 2016 issue of Nature Medicine by Lamas and colleagues investigates the interaction between Card9 and the gut microbiota in the generation of the microbiota-derived tryptophan metabolite. This study highlights the role of tryptophan in dampening intestinal inflammation in susceptible hosts.
基金This work was supported by the China Scholarship Council(CSC,[2019]110)The support by DSM Nutritional Products(Basel,Switzerland)for the analysis of vitamin D3 and metabolites is well appreciatedThe Ghent University Special Research Fund is acknowledged for the financial support to the UGCT Centre of Expertise(BOF.EXP.2017.0007).
文摘Background:Alterations in ambient temperature have been associated with multiple detrimental effects on broilers such as intestinal barrier disruption and dysbiosis resulting in systemic inflammation.Inflammation and 25-hydroxycholecalciferol(25-OH-D_(3))have shown to play a negative and positive role,respectively,in the regulation of bone mass.Hence the potential of 25-OH-D_(3)in alleviating heat induced bone alterations and its mechanisms was studied.Results:Heat stress(HS)directly induced a decrease in tibia material properties and bone mass,as demonstrated by lower mineral content,and HS caused a notable increase in intestinal permeability.Treatment with dietary 25-OH-D_(3)reversed the HS-induced bone loss and barrier leak.Broilers suffering from HS exhibited dysbiosis and increased expression of inflammatory cytokines in the ileum and bone marrow,as well as increased osteoclast number and activity.The changes were prevented by dietary 25-OH-D_(3)administration.Specifically,dietary 25-OH-D_(3)addition decreased abundance of B-and T-cells in blood,and the expression of inflammatory cytokines,especially TNF-α,in both the ileum and bone marrow,but did not alter the diversity and population or composition of major bacterial phyla.With regard to bone remodeling,dietary 25-OH-D_(3)supplementation was linked to a decrease in serum C-terminal cross-linked telopeptide of type I collagen reflecting bone resorption and a concomitant decrement in osteoclast-specific marker genes expression(e.g.cathepsin K),whereas it did not apparently change serum bone formation markers during HS.Conclusions:These data underscore the damage of HS to intestinal integrity and bone health,as well as that dietary 25-OH-D_(3)supplementation was identified as a potential therapy for preventing these adverse effects.
基金supported by grants from the Research Foundation–Flanders(11A6420N,1268823N to WC and LVH)a FWO Junior Research Project Grant(G055121N to REV)VIB.AG is a senior clinical researcher of the Research Foundation–Flanders(1805718N)。
文摘Hepatic encephalopathy,defined as neuropsychiatric dysfunction secondary to liver disease,is a frequent decompensating event in cirrhosis.Its clinical impact is highlighted by a notable increase in patient mortality rates and a concomitant reduction in overall quality of life.Systemically,liver disease,liver function failure,portosystemic shunting,and associated multi-organ dysfunction result in the increase of disease-causing neurotoxins in the circulation,which impairs cerebral homeostasis.Key circulating neurotoxins are ammonia and inflammatory mediators.In the brain,pathophysiology is less well understood,but is thought to be driven by glial cell dysfunction.Astrocytes are the only brain resident cells that have ammonia-metabolizing machinery and are therefore putatively most susceptible to ammonia elevation.Based on a large body of mostly in vitro evidence,ammonia-induced cellular and molecular disturbances include astrocyte swelling and oxidative stress.Microglia,the brain resident macrophages,have been linked to the translation of systemic inflammation to the brain microenvironment.Recent evidence from animal studies has provided novel insights into old and new downstream effects of astrocyte and microglial dysfunction such as toxin clearance disruption and myeloid cell attraction to the central nervous system parenchyma.Furthermore,state of the art research increasingly implicates neuronal dysfunction and possibly even irreversible neuronal cell death.Cell-type specific investigation in animal models highlights the need for critical revision of the contribution of astrocytes and microglia to well-established and novel cellular and molecular alterations in hepatic encephalopathy.In this review,we therefore give a current and comprehensive overview of causes,features,and consequences of astrocyte and microglial dysfunction in hepatic encephalopathy,including areas of interest for future investigation.
基金funded by the Ghent University Special Research Fund(BOF.PDO.2022.0002.01)Projects of International Cooperation of Henan Province(232102520016)National Natural Science Foundation of Henan Province(242300420159).
文摘Background Heat stress(HS) incidence is associated with the accumulation of reactive substances, which might be associated with bone loss. N-Acetylcysteine(NAC) exhibits strong antioxidants due to its sulfhydryl group and being as the precursor for endogenous glutathione synthesis. Therefore, interplay between oxidative stress and bone turnover of broilers and the effects of dietary NAC inclusion on antioxidant capability and “gut-bone” axis were evaluated during chronic HS.Results Implementing cyclic chronic HS(34 ℃ for 7 h/d) evoked reactive oxygen species excessive production and oxidant stress, which was accompanied by compromised tibia mass. The RNA-seq of proximal tibia also revealed the enrichment of oxidation–reduction process and inflammatory outbursts during HS. Although no notable alterations in the growth performance and cecal microbiota were found, the diet contained 2 g/kg NAC enhanced the antioxidant capability of heat-stressed broiler chickens by upregulating the expression of Nrf2 in the ileum, tibia, and bone marrow. Simultaneously, NAC tended to hinder NF-κB pathway activation and decreased the m RNA levels of the proinflammatory cytokines in both the ileum and bone marrow. As a result, NAC suppressed osteoclastogenesis and osteoclast activity, thereby increasing osteocyte-related gene expression. Furthermore, the inclusion of NAC tended to increase the ash content and density of the whole tibia, as well as improve cortical thickness and bone volume of the diaphysis.Conclusions These findings HS-mediated outburst of oxidant stress accelerates bone resorption and negatively regulates the bone quality of tibia, which is inhibited by NAC in broilers.
基金Supported by the Region Auvergne-Rhone-Alpes and FEDER,No.Thématiques émergentes and Pack Ambition Recherchethe French Government IDEX-ISITE Initiative,No.16-IDEX-0001-CAP 20-25the Ministère de la Recherche et de la Technologie,INSERM and University of Clermont Auvergne,No.UMR1071.
文摘BACKGROUND Chronic abdominal pain is the most common cause for gastroenterology consultation and is frequently associated with functional gastrointestinal disorders including irritable bowel syndrome and inflammatory bowel disease. These disorders present similar brain/gut/microbiota trialogue alterations, associated with abnormal intestinal permeability, intestinal dysbiosis and colonic hypersensitivity(CHS). Intestinal dysbiosis can alter colon homeostasis leading to abnormal activation of the innate immunity that promotes CHS, perhaps involving the toll-like receptors(TLRs), which play a central role in innate immunity.AIM To understand the mechanisms between early life event paradigm on intestinal permeability, fecal microbiota composition and CHS development in mice with TLRs expression in colonocytes.METHODS Maternal separation model(NMS) CHS model, which mimics deleterious events in childhood that can induce a wide range of chronic disorders during adulthood were used. Colonic sensitivity of NMS mice was evaluated by colorectal distension(CRD) coupled with intracolonic pressure variation(IPV) measurement. Fecal microbiota composition was analyzed by 16S rRNA sequencing from weaning to CRD periods. TLR mRNA expression was evaluated in colonocytes.Additionally, the effect of acute intrarectal instillation of the TLR5 agonist flagellin(FliC) on CHS in adult naive wildtype mice was analyzed.RESULTS Around 50% of NMS mice exhibited increased intestinal permeability and CHS associated with intestinal dysbiosis, characterized by a significant decrease of species richness, an alteration of the core fecal microbiota and a specific increased relative abundance of flagellated bacteria. Only TLR5mRNA expression was increased in colonocytes of NMS mice with CHS. Acute intrarectal instillation of FliC induced transient increase of IPV, reflecting transient CHS appearance.CONCLUSION Altogether, these data suggest a pathophysiological continuum between intestinal dysbiosis and CHS, with a role for TLR5.
基金supported by the Research Foundation Flanders(FWO)The Foundation for Alzheimer’s Research Belgium(SAO-FRA)+1 种基金European Union Cost action MouseAge(BM1402)the Baillet Latour Fund(all to SS and REV)
文摘Due to the aging of the population and despite the enormous scientific effort,Alzheimer's disease remains one of the biggest medical and pharmaceutical challenges in current medicine.Novel insights highlight the importance of neuroinflammation as an undeniable player in the onset and progression of Alzheimer's disease.Tumor necrosis factor is a master inflammatory cytokine that signals via tumor necrosis factor receptor 1 and tumor necrosis factor receptor 2,but that also regulates several brain functions in health and disease.However,clinical trials investigating drugs that interfere with the tumor necrosis factor pathway in Alzheimer's disease led to inconclusive results,partially because not only the pro-inflammatory tumor necrosis factor/tumor necrosis factor receptor 1,but also the beneficial tumor necrosis factor/tumor necrosis factor receptor 2 signaling was antagonized in these trials.We recently found that tumor necrosis factor is the main upregulated cytokine in the choroid plexus of Alzheimer's disease patients,signaling via tumor necrosis factor receptor 1.In agreement with this,choroidal tumor necrosis factor/tumor necrosis factor receptor 1 signaling was also upregulated in different Alzheimer's disease mouse models.Interestingly,both genetic and nanobody-based pharmacological blockage of tumor necrosis factor receptor 1 signaling was accompanied by favorable effects on Alzheimer's disease-associated inflammation,choroidal morphology and cognitive functioning.Here,we briefly summarize the detrimental effects that can be mediated by tumor necrosis factor/tumor necrosis factor receptor 1 signaling in(early) Alzheimer's disease,and the consequences this might have on the disease progression.As the main hypothesis in Alzheimer's disease clinical trials is still based on the amyloid beta-cascade,the importance of Alzheimer's disease-associated neuroinflammation urge the development of novel therapeutic strategies that might be effective in the early stages of Alzheimer's disease and prevent the irreversible neurodegeneration and resulting memory decline.
文摘B lymphoma Moloney murine leukemia virus insertion region 1 (BMI1), a core member of polycomb repressive complex 1 (PRC1), has been intensely investigated in the field of cancer epigenetics for decades. Widely known as a critical regulator in cellular physiology, BMI1 is essential in self-renewal and differentiation in different lineages of stem cells. BMI1 also plays a significant role in cancer etiology for its involvement in pathological progress such as epithelial–mesenchymal transition (EMT) and cancer stem cell maintenance, propagation, and differentiation. Importantly, overexpression of BMI1 is predictive for drug resistance, tumor recurrence, and eventual therapy failure of various cancer subtypes, which renders the pharmacological targeting at BMI1 as a novel and promising therapeutic approach. The study on prostate cancer, a prevalent hormone-related cancer among men, has promoted enormous research advancements in cancer genetics and epigenetics. This review summarizes the role of BMI1 as an oncogenic and epigenetic regulator in tumor initiation, progression, and relapse of prostate cancer.
文摘Type 2^(high) asthma,which accounts for the majority of asthma cases,is driven by Th2 cells that produce cytokines such as IL-4,IL-5,and IL-13.These cytokines promote several features of the disease,including eosinophilia,IgE production,bronchial hyperresponsiveness(BHR),mucus hypersecretion,and susceptibility to exacerbations.In contrast,type 2^(low) asthma is characterized by the presence of neutrophils and reduced responsiveness to corticosteroids.In recent years,advances in our understanding of the distinct mechanisms at play in each asthma endotype have paved the way for the development of targeted therapies tailored to specific patient profiles.In this review,we first explore the underlying immunological mechanisms of various asthma endotypes.We also provide an overview of the different types of immunotherapies currently available to asthmatic patients and their clinical efficacy.Finally,we highlight emerging therapeutic strategies that hold promise for improving asthma management in the future.
文摘Pneumonia, the most typical and frequent lower respiratory tract infection （LRTI）, is a leading cause of health problems in the United States. Bacteria represent the most prevailing cause of pneumonia in both children and adults. Although pneumonia with a single bacterial infection is common, a significant portion of patients with pneumonia is polymicrobial. This infection is often complexed with other physiological factors such as cytokines and growth factors. Nontypeable Haemophilus influenzae （NTHi） is the most frequently recovered Gram-negative bacterial pathogen in the respiratory system and induces strong inflammatory responses. NTHi also synergizes with other respiratory pathogens, such as Streptococcus pneumoniae and respiratory viruses and pro-inflammatory cytokines, such as tumor necrosis factor-alpha （TNF-α）. It is noteworthy that NTHi not only synergizes with growth factors such as transforming growth factor-beta （TGF-β）, but also utilizes growth factor receptors such as TGF-β receptor and epidermal growth factor receptor （EGFR）, to enhance inflammatory responses. Although appropriate inflammation is a protective response against invading pathogens, an uncontrolled inflammatory response is often detrimental to the host. Thus, inflammation must be tightly regulated. The human immune system has evolved strategies for controlling overactive inflammatory response. One such important mechanism is via regulation of negative feedback regulators for inflammation. CYLD, a multifunctional deubiquitinase, was originally reported as a tumor suppressor, but was recently identified as a negative regulator for nuclear factor-kappa B （NF-κB） signaling. It is induced by NTHi and TNF-α via a NF-κB-dependent mechanism, thereby serving as an inducible negative feedback regulator for tightly controlling inflammation in NTHi infection.
文摘Cytotoxic T lymphocytes （CTLs） and natural killer （NK） cells contribute to the body＇s immune defenses. Current chimeric antigen receptor （CAR）-modified T cell immunotherapy shows strong promise for treating var- ious cancers and infectious diseases. Although CAR- modified NK cell immunotherapy is rapidly gaining attention, its clinical applications are mainly focused on preclinical investigations using the NK92 cell line. Despite recent advances in CAR-modified T cell immunotherapy, cost and severe toxicity have hindered its widespread use. To alleviate these disadvantages of CAR-modified T cell immunotherapy, additional cyto- toxic cell-mediated immunotherapies are urgently nee- ded. The unique biology of NK cells allows them to serve as a safe, effective, alternative immunotherapeutic strategy to CAR-modified T cells in the clinic. While the fundamental mechanisms underlying the cytotoxicity and side effects of CAR-modified T and NK cell immunotherapies remain poorly understood, the for- mation of the immunological synapse （IS） between CAR- modified T or NK cells and their susceptible target cells is known to be essential. The role of the IS in CAR T and NK cell immunotherapies will allow scientists to harness the power of CAR-modified T and NK cells to treat can- cer and infectious diseases. In this review, we highlight the potential applications of CAR-modified NK cells to treat cancer and human immunodeficiency virus （HIV）, and discuss the challenges and possible future directions of CAR-modified NK cell immunotherapy, as well as the importance of understanding the molecular mechanisms of CAR-modified T cell- or NK cell-medi- ated cytotoxicity and side effects, with a focus on the CAR-modified NK cell IS.
基金The Research Foundation-Flanders(FWO,personal PhD fellowship grant 1S38920N,awarded to M.B.)Marie Sktodowska-Curie Actions(MSCA,Individual Fellowship CHORPATH-897918,awarded to M.P.)+4 种基金R.H.was funded by Marie Sktodowska-Curie Actions COFUND(OMICS@VIB)I.E.H.was funded by FWO personal PhD fellowship grant(1S04020N)and iBOF(Next-BIOREF,011B4220)C.D.and W.B.were funded by Stanford University's Global Climate and Energy Project"Towards New Degradable Lignin Types"and W.B.by the ERC-Advanced Grant POPMET.We also thank the Bijzonder Onderzoeksfonds-Zware Apparatuur of Ghent University for the Fourier transform ion cyclotron resonance mass spectrometer(174PZA05)the Hercules program of Ghent University for the Synapt QTOF High Definition MS(grant AUGE/014)V.I.T.and J.R.were funded by the DOE Great Lakes Bioenergy Research Center(DOE BER Office of Science DESC0018409).
文摘Although the plant kingdom provides an enormous diversity of metabolites with potentially beneficial applications for humankind,a large fraction of these metabolites and their biosynthetic pathways remain unknown.Resolving metabolite structures and their biosynthetic pathways is key to gaining biological understanding andto allow metabolic engineering.In orderto retrieve novel biosynthetic genes involved in specialized metabolism,we developed a novel untargeted method designated as qualitative trait GWAs(QT-GWAS)that subjects qualitative metabolic traits to a genome-wide association study,while the conventional metabolite GWAS(mGWAS)mainly considers the quantitative variation of metabolites.As a proof of the validity of QT-GWAS,23 and 15of the retrieved associations identified in Arabidopsis thaliana by QTGWAS and mGWAS,respectively,were supported by previous research.Furthermore,seven genemetabolite associations retrieved by QT-GWAS were confirmed in this study through reverse genetics combined with metabolomics and/or in vitro enzyme assays.As such,we established that CYTOCHROME P450706A5(CYP706A5)is involved in the biosynthesis of chroman derivatives,UDP-GLYCOSYLTRANSFERASE 76C3(UGT76C3)is able tohexosylate guanine in vitro and in planta,and SULFOTRANSFERASE 202B1(SULT202B1)catalyzes the sulfation of neolignans in vitro.Collectively,our study demonstrates that the untargeted QT-GWAS method can retrieve valid gene-metabolite associations at the level of enzyme-encoding genes,even new associations that cannot be found by the conventional mGwAs,providing a new approach for dissecting qualitative metabolic traits.
基金supported by the grants from the National Natural Science Foundation of China(81970503,82100670,82202021and 82270606)Chinese Institutes for Medical Research+7 种基金Beijing(CX24PY16)R&D Program of Beijing Municipal Education Commission(KZ202210025036)Beijing Municipal Administration of Hospitals’Ascent Plan(DFL20220103)Beijing Nova Program(Z211100002121036)Youth Beijing Scholar(035)and the Reform and Development Program of Beijing Institute of Respiratory Medicine(Ggyfz202403)Generation of reagents and mutant mice are also supported by the National Institutes of Health(R01 DK108894R21 CA164970 and R21 CA221702)Department of Defense Award W81XWH-16-0464。
文摘Hepatic ischemia–reperfusion injury(HIRI)is an important cause of liver injury following liver transplantation and major resections,and neutrophils are the key effector cells in HIRI.Double-negative T regulatory cells(DNT)are increasingly recognized as having critical regulatory functions in the immune system.Whether DNT expresses distinct immunoregulatory mechanisms to modulate neutrophils,as in HIRI,remains largely unknown.In this study,we found that murine and human DNT highly expressed CD39that protected DNT from extracellular ATP-induced apoptosis and generated adenosine in tandem with CD73,to induce high levels of neutrophil apoptosis.Furthermore,extracellular adenosine enhanced DNT survival and suppressive function by upregulating survivin and NKG2D expression via the A2AR/pAKT/FOXO1 signaling pathway.Adoptive transfer of DNT ameliorated HIRI in mice through the inhibition of neutrophils in a CD39-dependent manner.Lastly,the adoptive transfer of A2ar^(-/-)DNT validated the importance of adenosine/A2AR signaling,in promoting DNT survival and immunomodulatory function to protect against HIRI in vivo.In conclusion,purinergic signaling is crucial for DNT homeostasis in HIRI.Augmentation of CD39 or activation of A2AR signaling in DNT may provide novel therapeutic strategies to target innate immune disorders.
基金This work was supported by grants from the National Natural Science Foundation of China （81572766 and 31771630）, the National Key Research and Development Program of China （2017YFA0103800）, Guangdong Innovative and Entrepreneurial Research Team Program （2016ZT06S029）, Guangdong Natural Science Foundation （2016A030313215 and 2016A030313238）, SYSU Young Teachers Training Program （16YKZD14） and grants （CA101795 and IU54CA210181） from U.S. National Cancer Institute, National Institutes of Health （NIH）, DOD （W81XWH-16- 1-0417）, and CPRIT （DP150099, RP170537, and RP150611）.
文摘The differentiation status of neuroblastoma （NB） strongly correlates with its clinical outcomes; however, the molecular mechanisms driving maintenance of sternness and differentiation remain poorly understood. Here, we show that plant homeodomain finger-containing protein 20 （PHF20） functions as a critical epigenetic regulator in sustaining stem cell-like phenotype of NB by using CRISPR/Casg-based targeted knockout （KO） for high-throughput screening of gene function in NB cell differentiation. The expression of PHF20 in NB was significantly associated with high aggressiveness of the tumor and poor outcomes for NB patients. Deletion of PHF20 inhibited NB cell proliferation, invasive migration, and stem ceU-Uke traits. Mechanistically, PHF20 interacts with poly（ADP-ribose） polymerase 1 （PARP1） and directly binds to promoter regions of octamer-binding transcription factor 4 （OCT4） and sex determining region Y-box 2 （SOX2） to modulate a histone mark associated with active transcription, trimethylation of lysine 4 on histone H3 protein subunit （H3K4me3）. Overexpression of OCT4 and SOX2 restored growth and progression of PHF20 KO tumor cells. Consistently, OCT4 and SOX2 protein levels in clinical NB specimens were positively correlated with PHF20 expression. Our results establish PHF20 as a key driver of NB stem cell-like properties and aggressive behaviors, with implications for prognosis and therapy.
基金FWO Research Grants G.0B96.20N(PV,PT),G.0C76.18N(PV),G.0B71.18N(PV)G.0A93.22N(PV)+9 种基金Special Research Fund UGent(Methusalem grant BOF16/MET_V/007(PV)BOF22/MET_V/007(PV)iBOF ATLANTIS grant 20/IBF/039(PV))EOS MODEL-IDI Grant(30826052)(PV)EOS CD-INFLADIS(40007512)(PV)Foundation against Cancer(F/2016/865,F/2020/1505)(PV).FWO fundamental research fellowship PhD grant(MRP)(11A7222N)FWO senior postdoctoral fellowship(CM)(12Y2122N)DFG research fellowship(CM)(MA 7770/1-1)Cancer Research Institute Ghent(CRIG)consortiaGhent Gut Inflammation Group(GGIG)consortia.Flanders Institute for Biotechnology(VIB).
文摘Acute systemic inflammation critically alters the function of the immune system,often promoting myelopoiesis at the expense of lymphopoiesis.In the thymus,systemic inflammation results in acute thymic atrophy and,consequently,impaired T-lymphopoiesis.The mechanism by which systemic inflammation impacts the thymus beyond suppressing T-cell development is still unclear.Here,we describe how the synergism between TL1A and IL-18 suppresses T-lymphopoiesis to promote thymic myelopoiesis.The protein levels of these two cytokines were elevated in the thymus during viral-induced thymus atrophy infection with murine cytomegalovirus(MCMV)or pneumonia virus of mice(PVM).In vivo administration of TL1A and IL-18 induced acute thymic atrophy,while thymic neutrophils expanded.Fate mapping with Ms4a3-Cre mice demonstrated that thymic neutrophils emerge from thymic granulocyte-monocyte progenitors(GMPs),while Rag1-Cre fate mapping revealed a common developmental path with lymphocytes.These effects could be modeled ex vivo using neonatal thymic organ cultures(NTOCs),where TL1A and IL-18 synergistically enhanced neutrophil production and egress.NOTCH blockade by the LY411575 inhibitor increased the number of neutrophils in the culture,indicating that NOTCH restricted steady-state thymic granulopoiesis.To promote myelopoiesis,TL1A,and IL-18 synergistically increased GM-CSF levels in the NTOC,which was mainly produced by thymic ILC1s.In support,TL1A-and IL-18-induced granulopoiesis was completely prevented in NTOCs derived from Csf2rb-/-mice and by GM-CSFR antibody blockade,revealing that GM-CSF is the essential factor driving thymic granulopoiesis.Taken together,our findings reveal that TL1A and IL-18 synergism induce acute thymus atrophy while promoting extramedullary thymic granulopoiesis in a NOTCH and GM-CSF-controlled manner.
文摘Regulatory T （Treg） cells play a central role in regulating peripheral immune tolerance and preventing autoimmunity. Despite the extensive studies on the development of Treg cells, the molecular mechanisms that maintain the population of committed Treg cells remain poorly understood. We show here that Treg-conditional ablation of the kinase TAK1 reduced the number of Treg cells in the peripheral lymphoid organs, causing abnormal activation of conventional T cells and autoimmune symptoms. Using an inducible gene knockout approach, we further demonstrate that TAK1 is crucial for the survival of Treg cells. Expression of a constitutively active IKB kinase partially restored the level of Treg cells in the TAKITreg-KO mice. These results suggest a crucial role for TAK1 for maintaining the survival of committed Treg cells under physiololzical conditions.
文摘Human cells contain two types of adenosine deaminases(ADA)each with unique properties:ADA1,which is present in all cells where it modulates intracellular functions and extracellular signaling,and ADA2,which is secreted by immune cells.The exact intracellular functions of ADA2 remain undetermined and less defined than those of ADA1.ADA2 has distinct characteristics,such as low adenosine affinity,heparin-binding ability,and putative lysosomal entry.Here,we confirm that ADA2 is a lysosomal protein that binds toll-like receptor 9(TLR9)agonists,specifically CpG oligodeoxynucleotides(CpG ODNs).We show that interferon-alpha(IFN-α)is secreted in response to TLR9 activation by CpG ODNs and natural DNA and markedly increases when ADA2 expression is downregulated in plasmacytoid dendritic cells(pDCs).Additionally,the pretreatment of pDCs with RNA further stimulates IFN-αsecretion by pDCs after activation with CpG ODNs.Our findings indicate that ADA2 regulates TLR9 responses to DNA in activated pDCs.In conclusion,decreasing ADA2 expression or blocking it with specific oligonucleotides can enhance IFN-αsecretion from pDCs,improving immune responses against intracellular infections and cancer.
基金K.B.acknowledges financial support from the European Research Council(ERC)under the European Union's Horizon 2020 research and innovation program(No.648124)from the Ghent University Special Research Fund(No.01B04912)+3 种基金with gratitude.J.L.gratefully acknowledges the financial support from the China Scholarship Council(CSC)(No.201506750012)the Ghent University Special Research Fund(No.01SC1416)T.H.and J.G.acknowledges financial support from the Fonds Wetenschappelijk Onderzoek(No.G.0559.16N)Ghent University(BOF-GOA)(No.BOF13/GOA010)。
文摘Fluorescence microscopy is the method of choice for studying intracellular dynamics.However,its success depends on the.availability of specific and stable markers.A prominent example of markers that are rapidly gaining interest are nanobodies(Nbs.-15 kDa),which can be functionalized with bright and photostable organic fluorophores.Due to their relatively small size and high specificity,Nbs offer great potential for high-quality long-term subcellular imaging,but suffer from the fact that they cannot spontaneously cross the plasma membrane of live cells.We have recently discovered that laser-induced photoporation is well suited to deliver extrinsic labels to living cells without compromising their viability.Being a laser-based technology,it is readily compatible with light microscopy and the typical cell recipients used for that.Spurred by these promising initial results,we demonstrate here for the first time successful long-term imaging of specific subcellular structures with labeled nanobodies in living cells.We illustrate this using Nbs that target GFP/YFP-protein constructs accessible in the cytoplasm,actin-bundling protein Fascin,and the histone H2A/H2B heterodimers.With an efficiency of more than 80%labeled cells and minimal toxicity(-2%),photoporation proved to be an excellent intracellular delivery method for Nbs.Time-lapse microscopy revealed that cell division rate and migration remained unaffected,confirming excellent cell viability and functionality.We conclude that laser-induced photoporation labeled Nbs can be easily delivered into living cells,laying the foundation for further development of a broad range of Nbs with intracellular targets as a toolbox for long-term live-cell microscopy.
基金supported by the Flemish Fund for Scientific Research(FWO Vlaanderen,12J9116N,12JG119N,12U7718N,1S15519N,and G099618N)the Belgian Charcot Foundation(FCS-2016-EG7,R-8676,and R-6832)+4 种基金the Interreg V‐A EMR program(EURLIPIDS,EMR23)the special research fund UHasselt(BOF)JMN is supported by a National Institutes of Health Grant(R01 DK062388)supported by the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation program(640116)by a SALK grant from the government of Flanders and by an Odysseus grant of the Research Foundation Flanders,Belgium(FWO).
文摘The imbalance between pathogenic and protective T cell subsets is a cardinal feature of autoimmune disorders such as multiple sclerosis(MS).Emerging evidence indicates that endogenous and dietary-induced changes in fatty acid metabolism have a major impact on both T cell fate and autoimmunity.To date,however,the molecular mechanisms that underlie the impact of fatty acid metabolism on T cell physiology and autoimmunity remain poorly understood.Here,we report that stearoyl-CoA desaturase-1(SCD1),an enzyme essential for the desaturation of fatty acids and highly regulated by dietary factors,acts as an endogenous brake on regulatory T-cell(Treg)differentiation and augments autoimmunity in an animal model of MS in a T cell-dependent manner.Guided by RNA sequencing and lipidomics analysis,we found that the absence of Scd1 in T cells promotes the hydrolysis of triglycerides and phosphatidylcholine through adipose triglyceride lipase(ATGL).ATGL-dependent release of docosahexaenoic acid enhanced Treg differentiation by activating the nuclear receptor peroxisome proliferator-activated receptor gamma.Our findings identify fatty acid desaturation by SCD1 as an essential determinant of Treg differentiation and autoimmunity,with potentially broad implications for the development of novel therapeutic strategies and dietary interventions for autoimmune disorders such as MS.
文摘After activation by antigen-presenting cells,naive,antigenspecific CD41 T cells differentiate into effector T cells.Two decades ago,Coffman and Mosman first discovered the heterogeneity of effector T cells,which were named as Th1 or Th2 cells.1 Th1 and Th2 cells are differentially induced and are involved in immunity against intracellular and extracellular pathogens,respectively,as well as immunopathologies such as autoimmunity and allergy.The Th1/Th2 dichotomy dominated the field of immune regulation until about 4 years ago when IL-17-expressing T cells were proposed to be a third lineage of helper T cells.
基金This work was supported by grants from the National Key Research and Development Program of China （2017YFA0103800）, the National Natural Science Foundation of China （81572766 and 31771630）, Guangdong Innovative and Entrepreneurial Research Team Program （2016ZT06S029）, 6uangdong Natural Science Foundation （2016A030313215 and 2016A030313238）, SYSU Young Teachers Training Program （16YKZD14）, the National Cancer Institute （NCl）, the National Institutes of Health （NIH） （ROICA090327 and RO1CA101795）, and the Cancer Prevention and Research Institute of Texas （CPRIT） （RP170537）.
文摘Mutations in tumors can create a state of increased cellular plasticity that promotes resistance to treatment. Thus, there is an urgent need to develop novel strategies for identifying key factors that regulate cellular plasticity in order to combat resistance to chemotherapy and radiation treatment. Here we report that prostate epithelial cell reprogramming could be exploited to identify key factors required for promoting prostate cancer tumorigenesis and cellular plasticity. Deletion of phosphatase and tensin homolog （Pten） and transforming growth factor-beta receptor type 2 （Tgfbr2） may increase prostate epithelial cell reprogramming efficiency in vitro and cause rapid tumor development and early mortality in vivo. Tgfbr2 ablation abolished TGF-β signaling but increased the bone morphogenetic protein （BMP） signaling pathway through the negative regulator Tmeff1. Furthermore, increased BMP signaling promotes expression of the tumor marker genes ID1, Oct4, Nanog, and Sox2; ID1/STAT3/NANOG expression was inversely correlated with patient survival. Thus, our findings provide information about the molecular mechanisms by which BMP signaling pathways render stemness capacity to prostate tumor cells.
