Dendritic Cells Regulate Extrafollicular Autoreactive B Cells via T Cells Expressing Fas and Fas Ligand.
The extrafollicular (EF) plasmablast response to self-antigens that contain Toll-like receptor (TLR) ligands is prominent in murine lupus models and some bacterial infections,but the inhibitors and activators involved have not been fully delineated. Here,we used two conventional dendritic cell (cDC) depletion systems to investigate the role of cDCs on a classical TLR-dependent autoreactive EF response elicited in rheumatoid-factor B cells by DNA-containing immune complexes. Contrary to our hypothesis,cDC depletion amplified rather than dampened the EF response in Fas-intact but not Fas-deficient mice. Further,we demonstrated that cDC-dependent regulation requires Fas and Fas ligand (FasL) expression by T cells,but not Fas expression by B cells. Thus,cDCs activate FasL-expressing T cells that regulate Fas-expressing extrafollicular helper T (Tefh) cells. These studies reveal a regulatory role for cDCs in B cell plasmablast responses and provide a mechanistic explanation for the excess autoantibody production observed in Fas deficiency.
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产品类型:
产品号#:
19754
19754RF
产品名:
Bernard BA et al. (JUL 1992)
Biochemical and biophysical research communications 186 2 977--83
Identification of synthetic retinoids with selectivity for human nuclear retinoic acid receptor gamma.
The action of retinoids on gene regulation is mediated by three distinct nuclear retinoic acid receptor (RAR) subtypes called RAR alpha,beta and gamma. Since RAR gamma is predominantly expressed in adult skin,specific ligands for this subtype could (i) represent valuable tools to evaluate the biological role of RAR gamma in skin and (ii) provide therapeutic entities with a higher therapeutic index at lower teratogenic risk. Using in vitro binding studies and a functional transactivation assay,we have identified three compounds with high RAR gamma selectivity.
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产品类型:
产品号#:
72722
72724
72962
72964
产品名:
CD437
CD437
AM580
Saha K et al. (NOV 2011)
Proceedings of the National Academy of Sciences of the United States of America 108 46 18714--9
Surface-engineered substrates for improved human pluripotent stem cell culture under fully defined conditions
The current gold standard for the culture of human pluripotent stem cells requires the use of a feeder layer of cells. Here,we develop a spatially defined culture system based on UV/ozone radiation modification of typical cell culture plastics to define a favorable surface environment for human pluripotent stem cell culture. Chemical and geometrical optimization of the surfaces enables control of early cell aggregation from fully dissociated cells,as predicted from a numerical model of cell migration,and results in significant increases in cell growth of undifferentiated cells. These chemically defined xeno-free substrates generate more than three times the number of cells than feeder-containing substrates per surface area. Further,reprogramming and typical gene-targeting protocols can be readily performed on these engineered surfaces. These substrates provide an attractive cell culture platform for the production of clinically relevant factor-free reprogrammed cells from patient tissue samples and facilitate the definition of standardized scale-up friendly methods for disease modeling and cell therapeutic applications.
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产品类型:
产品号#:
05850
05857
05870
05875
85850
85857
85870
85875
产品名:
mTeSR™1
mTeSR™1
Han YK et al. (JAN 2013)
Biochemical and biophysical research communications 430 4 1329--1333
A possible usage of a CDK4 inhibitor for breast cancer stem cell-targeted therapy.
Cancer stem cells (CSCs) are one of the main reasons behind cancer recurrence due to their resistance to conventional anti-cancer therapies. Thus,many efforts are being devoted to developing CSC-targeted therapies to overcome the resistance of CSCs to conventional anti-cancer therapies and decrease cancer recurrence. Differentiation therapy is one potential approach to achieve CSC-targeted therapies. This method involves inducing immature cancer cells with stem cell characteristics into more mature or differentiated cancer cells. In this study,we found that a CDK4 inhibitor sensitized MDA-MB-231 cells but not MCF7 cells to irradiation. This difference appeared to be associated with the relative percentage of CSC-population between the two breast cancer cells. The CDK4 inhibitor induced differentiation and reduced the cancer stem cell activity of MDA-MB-231 cells,which are shown by multiple marker or phenotypes of CSCs. Thus,these results suggest that radiosensitization effects may be caused by reducing the CSC-population of MDA-MB-231 through the use of the CDK4 inhibitor. Thus,further investigations into the possible application of the CDK4 inhibitor for CSC-targeted therapy should be performed to enhance the efficacy of radiotherapy for breast cancer.
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产品类型:
产品号#:
05620
产品名:
MammoCult™人培养基试剂盒
Xing J et al. (MAY 2015)
Scientific Reports 5 November 2014 10038
A method for human teratogen detection by geometrically confined cell differentiation and migration
Unintended exposure to teratogenic compounds can lead to various birth defects; however current animal-based testing is limited by time,cost and high inter-species variability. Here,we developed a human-relevant in vitro model,which recapitulated two cellular events characteristic of embryogenesis,to identify potentially teratogenic compounds. We spatially directed mesoendoderm differentiation,epithelial-mesenchymal transition and the ensuing cell migration in micropatterned human pluripotent stem cell (hPSC) colonies to collectively form an annular mesoendoderm pattern. Teratogens could disrupt the two cellular processes to alter the morphology of the mesoendoderm pattern. Image processing and statistical algorithms were developed to quantify and classify the compounds' teratogenic potential. We not only could measure dose-dependent effects but also correctly classify species-specific drug (Thalidomide) and false negative drug (D-penicillamine) in the conventional mouse embryonic stem cell test. This model offers a scalable screening platform to mitigate the risks of teratogen exposures in human.
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产品类型:
产品号#:
05850
05857
05870
05875
07923
85850
85857
85870
85875
05270
05275
产品名:
Dispase (1 U/mL)
mTeSR™1
mTeSR™1
STEMdiff™ APEL™2 培养基
STEMdiff™ APEL™2 培养基
Zhao Y et al. (JUL 2010)
Nature cell biology 12 7 665--75
Cytosolic FoxO1 is essential for the induction of autophagy and tumour suppressor activity.
Autophagy is characterized by the sequestration of bulk cytoplasm,including damaged proteins and organelles,and delivery of the cargo to lysosomes for degradation. Although the autophagic pathway is also linked to tumour suppression activity,the mechanism is not yet clear. Here we report that cytosolic FoxO1,a forkhead O family protein,is a mediator of autophagy. Endogenous FoxO1 was required for autophagy in human cancer cell lines in response to oxidative stress or serum starvation,but this process was independent of the transcriptional activity of FoxO1. In response to stress,FoxO1 was acetylated by dissociation from sirtuin-2 (SIRT2),a NAD(+)-dependent histone deacetylase,and the acetylated FoxO1 bound to Atg7,an E1-like protein,to influence the autophagic process leading to cell death. This FoxO1-modulated cell death is associated with tumour suppressor activity in human colon tumours and a xenograft mouse model. Our finding links the anti-neoplastic activity of FoxO1 and the process of autophagy.
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产品类型:
产品号#:
73052
73054
产品名:
AGK2
S. Niyongere et al. (JUL 2018)
Leukemia
Heterogeneous expression of cytokines accounts for clinical diversity and refines prognostication in CMML.
Chronic myelomonocytic leukemia (CMML) is a clinically heterogeneous neoplasm in which JAK2 inhibition has demonstrated reductions in inflammatory cytokines and promising clinical activity. We hypothesize that annotation of inflammatory cytokines may uncover mutation-independent cytokine subsets associated with novel CMML prognostic features. A Luminex cytokine profiling assay was utilized to profile cryopreserved peripheral blood plasma from 215 CMML cases from three academic centers,along with center-specific,age-matched plasma controls. Significant differences were observed between CMML patients and healthy controls in 23 out of 45 cytokines including increased cytokine levels in IL-8,IP-10,IL-1RA,TNF-alpha$,IL-6,MCP-1/CCL2,hepatocyte growth factor (HGF),M-CSF,VEGF,IL-4,and IL-2RA. Cytokine associations were identified with clinical and genetic features,and Euclidian cluster analysis identified three distinct cluster groups associated with important clinical and genetic features in CMML. CMML patients with decreased IL-10 expression had a poor overall survival when compared to CMML patients with elevated expression of IL-10 (P = 0.017),even when adjusted for ASXL1 mutation and other prognostic features. Incorporating IL-10 with the Mayo Molecular Model statistically improved the prognostic ability of the model. These established cytokines,such as IL-10,as prognostically relevant and represent the first comprehensive study exploring the clinical implications of the CMML inflammatory state.
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Evaluation of strategies to modify Anti-SARS-CoV-2 monoclonal antibodies for optimal functionality as therapeutics.
The current global COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a public health crisis with more than 168 million cases reported globally and more than 4.5 million deaths at the time of writing. In addition to the direct impact of the disease,the economic impact has been significant as public health measures to contain or reduce the spread have led to country wide lockdowns resulting in near closure of many sectors of the economy. Antibodies are a principal determinant of the humoral immune response to COVID-19 infections and may have the potential to reduce disease and spread of the virus. The development of monoclonal antibodies (mAbs) represents a therapeutic option that can be produced at large quantity and high quality. In the present study,a mAb combination mixture therapy was investigated for its capability to specifically neutralize SARS-CoV-2. We demonstrate that each of the antibodies bind the spike protein and neutralize the virus,preventing it from infecting cells in an in vitro cell-based assay,including multiple viral variants that are currently circulating in the human population. In addition,we investigated the effects of two different mutations in the Fc portion (YTE and LALA) of the antibody on Fc effector function and the ability to alleviate potential antibody-dependent enhancement of disease. These data demonstrate the potential of a combination of two mAbs that target two different epitopes on the SARS-CoV2 spike protein to provide protection against SARS-CoV-2 infection in humans while extending serum half-life and preventing antibody-dependent enhancement of disease.
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Novel full-thickness biomimetic corneal model for studying pathogenesis and treatment of diabetic keratopathy
Diabetic keratopathy (DK),a significant complication of diabetes,often leads to corneal damage and vision impairment. Effective models are essential for studying DK pathogenesis and evaluating potential therapeutic interventions. This study developed a novel biomimetic full-thickness corneal model for the first time,incorporating corneal epithelial cells,stromal cells,endothelial cells,and nerves to simulate DK conditions in vitro. By exposing the model to a high-glucose (HG) environment,the pathological characteristics of DK,including nerve bundle disintegration,compromised barrier integrity,increased inflammation,and oxidative stress,were successfully replicated. Transcriptomic analysis revealed that HG downregulated genes associated with axon and synapse formation while upregulating immune response and oxidative stress pathways,with C-C Motif Chemokine Ligand 5 (CCL5) identified as a key hub gene in DK pathogenesis. The therapeutic effects of Lycium barbarum glycopeptide (LBGP) were evaluated using this model and validated in db/db diabetic mice. LBGP promoted nerve regeneration,alleviated inflammation and oxidative stress in both in vitro and in vivo models. Notably,LBGP suppressed the expression of CCL5,highlighting its potential mechanism of action. This study establishes a robust biomimetic platform for investigating DK and other corneal diseases,and identifies LBGP as a promising therapeutic candidate for DK. These findings provide valuable insights into corneal disease mechanisms and pave the way for future translational research and clinical applications. Graphical abstractImage 1 Highlights•A full-thickness biomimetic corneal model containing corneal epithelium,nerves,stroma,and endothelium was constructed.•Using this model,the pathological characteristics of diabetic keratopathy were successfully replicated in vitro.•Lycium barbarum glycopeptide (LBGP) alleviated high-glucose-induced damage in vitro and in vivo models.•CCL5 plays an important role in the pathogenesis of diabetic keratopathy.
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