Schrenk-Siemens K et al. (JAN 2014)
Nature neuroscience 18 1 10--16
PIEZO2 is required for mechanotransduction in human stem cell-derived touch receptors.
Human sensory neurons are inaccessible for functional examination,and thus little is known about the mechanisms mediating touch sensation in humans. Here we demonstrate that the mechanosensitivity of human embryonic stem (hES) cell-derived touch receptors depends on PIEZO2. To recapitulate sensory neuron development in vitro,we established a multistep differentiation protocol and generated sensory neurons via the intermediate production of neural crest cells derived from hES cells or human induced pluripotent stem (hiPS) cells. The generated neurons express a distinct set of touch receptor-specific genes and convert mechanical stimuli into electrical signals,their most salient characteristic in vivo. Strikingly,mechanosensitivity is lost after CRISPR/Cas9-mediated PIEZO2 gene deletion. Our work establishes a model system that resembles human touch receptors,which may facilitate mechanistic analysis of other sensory subtypes and provide insight into developmental programs underlying sensory neuron diversity.
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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
M. Ventre et al. (jul 2019)
Journal of biomedical materials research. Part A
Biochemical and biophysical stimuli of stem cell niches finely regulate the self-renewal/differentiation equilibrium. Replicating this in vitro is technically challenging,making the control of stem cell functions difficult. Cell derived matrices capture certain aspect of niches that influence fate decisions. Here,aligned fibrous matrices synthesized by MC3T3 cells were produced and the role of matrix orientation and stiffness on the maintenance of stem cell characteristics and adipo- or osteo-genic differentiation of murine mesenchymal stem cells (mMSCs) was investigated. Decellularized matrices promoted mMSC proliferation. Fibrillar alignment and matrix stiffness work in concert in defining cell fate. Soft matrices preserve stemness,whereas stiff ones,in presence of biochemical supplements,promptly induce differentiation. Matrix alignment impacts the homogeneity of the cell population,that is,soft aligned matrices ameliorate the spontaneous adipogenic differentiation,whereas stiff aligned matrices reduce cross-differentiation. We infer that mechanical signaling is a dominant factor in mMSC fate decision and the matrix alignment contributes to produce a more homogeneous environment,which results in a uniform response of cells to biophysical environment. Matrix thus produced can be obtained in vitro in a facile and consistent manner and can be used for homogeneous stem cell amplification or for mechanotransduction-related studies.
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Engineering an Escherichia coli strain for production of long single-stranded DNA
AbstractLong single-stranded DNA (ssDNA) is a versatile molecular reagent with applications including RNA-guided genome engineering and DNA nanotechnology,yet its production is typically resource-intensive. We introduce a novel method utilizing an engineered Escherichia coli ‘helper’ strain and phagemid system that simplifies long ssDNA generation to a straightforward transformation and purification procedure. Our method obviates the need for helper plasmids and their associated contamination by integrating M13mp18 genes directly into the E. coli chromosome. We achieved ssDNA lengths ranging from 504 to 20 724 nt with titers up to 250 μg/l following alkaline lysis purification. The efficacy of our system was confirmed through its application in primary T-cell genome modifications and DNA origami folding. The reliability,scalability and ease of our approach promise to unlock new experimental applications requiring large quantities of long ssDNA. Graphical Abstract Graphical Abstract
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产品类型:
产品号#:
20144
18000
产品名:
EasySep™缓冲液
EasySep™磁极
D. Stanojević et al. (Jul 2024)
Nature Communications 15 4
Rockfish: A transformer-based model for accurate 5-methylcytosine prediction from nanopore sequencing
DNA methylation plays an important role in various biological processes,including cell differentiation,ageing,and cancer development. The most important methylation in mammals is 5-methylcytosine mostly occurring in the context of CpG dinucleotides. Sequencing methods such as whole-genome bisulfite sequencing successfully detect 5-methylcytosine DNA modifications. However,they suffer from the serious drawbacks of short read lengths and might introduce an amplification bias. Here we present Rockfish,a deep learning algorithm that significantly improves read-level 5-methylcytosine detection by using Nanopore sequencing. Rockfish is compared with other methods based on Nanopore sequencing on R9.4.1 and R10.4.1 datasets. There is an increase in the single-base accuracy and the F1 measure of up to 5 percentage points on R.9.4.1 datasets,and up to 0.82 percentage points on R10.4.1 datasets. Moreover,Rockfish shows a high correlation with whole-genome bisulfite sequencing,requires lower read depth,and achieves higher confidence in biologically important regions such as CpG-rich promoters while being computationally efficient. Its superior performance in human and mouse samples highlights its versatility for studying 5-methylcytosine methylation across varied organisms and diseases. Finally,its adaptable architecture ensures compatibility with new versions of pores and chemistry as well as modification types. Subject terms: Genome informatics,Epigenomics,Computational models,DNA sequencing,DNA methylation
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产品类型:
产品号#:
100-0483
100-0484
产品名:
Hausser Scientificᵀᴹ 明线血球计数板
ReLeSR™
M. Lopez-Cavestany et al. (Aug 2024)
ACS Nano 18 34
Superhydrophobic Array Devices for the Enhanced Formation of 3D Cancer Models
During the metastatic cascade,cancer cells travel through the bloodstream as circulating tumor cells (CTCs) to a secondary site. Clustered CTCs have greater shear stress and treatment resistance,yet their biology remains poorly understood. We therefore engineered a tunable superhydrophobic array device (SHArD). The SHArD-C was applied to culture a clinically relevant model of CTC clusters. Using our device,we cultured a model of cancer cell aggregates of various sizes with immortalized cancer cell lines. These exhibited higher E-cadherin expression and are significantly more capable of surviving high fluid shear stress-related forces compared to single cells and model clusters grown using the control method,helping to explain why clustering may provide a metastatic advantage. Additionally,the SHArD-S,when compared with the AggreWell 800 method,provides a more consistent spheroid-forming device culturing reproducible sizes of spheroids for multiple cancer cell lines. Overall,we designed,fabricated,and validated an easily tunable engineered device which grows physiologically relevant three-dimensional (3D) cancer models containing tens to thousands of cells.
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产品类型:
产品号#:
34811
34815
34821
34825
34850
34860
产品名:
AggreWell™ 800 24孔板,1个
AggreWell™ 800 24孔板,5个
AggreWell™ 800 6孔板,1个
AggreWell™ 800 6孔板,5个
AggreWell™ 800 24孔板启动套装
AggreWell™ 800 6孔板启动套装
B. S. Marro et al. (dec 2019)
Cell reports 29 10 3293--3302.e3
Discovery of Small Molecules for the Reversal of T Cell Exhaustion.
Inhibitory receptors (IRs) function as critical regulators of immune responses by tempering T cell activity. In humans,several persisting viruses as well as cancers exploit IR signaling by upregulating IR ligands,resulting in suppression of T cell function (i.e.,exhaustion). This allows escape from immune surveillance and continuation of disease. Here,we report the design,implementation,and results of a phenotypic high-throughput screen for molecules that modulate CD8+ T cell activity. We identify 19 compounds from the ReFRAME drug-repurposing collection that restore cytokine production and enhance the proliferation of exhausted T cells. Analysis of our top hit,ingenol mebutate,a protein kinase C (PKC) inducing diterpene ester,reveals a role for this molecule in overriding the suppressive signaling cascade mediated by IR signaling on T cells. Collectively,these results demonstrate a disease-relevant methodology for identifying modulators of T cell function and reveal new targets for immunotherapy.
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J. L. Slack et al. (feb 2011)
Cellular and molecular life sciences : CMLS 68 4 709--20
Protein arginine deiminase 4: a target for an epigenetic cancer therapy.
The recent approvals of anticancer therapeutic agents targeting the histone deacetylases and DNA methyltransferases have highlighted the important role that epigenetics plays in human diseases,and suggested that the factors controlling gene expression are novel drug targets. Protein arginine deiminase 4 (PAD4) is one such target because its effects on gene expression parallel those observed for the histone deacetylases. We demonstrated that F- and Cl-amidine,two potent PAD4 inhibitors,display micromolar cytotoxic effects towards several cancerous cell lines (HL-60,MCF7 and HT-29); no effect was observed in noncancerous lines (NIH 3T3 and HL-60 granulocytes). These compounds also induced the differentiation of HL-60 and HT29 cells. Finally,these compounds synergistically potentiated the cell killing effects of doxorubicin. Taken together,these findings suggest PAD4 inhibition as a novel epigenetic approach for the treatment of cancer,and suggest that F- and Cl-amidine are candidate therapeutic agents for this disease.
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Polyglutamine Disease Modeling: Epitope Based Screen for Homologous Recombination using CRISPR/Cas9 System.
We have previously reported the genetic correction of Huntington's disease (HD) patient-derived induced pluripotent stem cells using traditional homologous recombination (HR) approaches. To extend this work,we have adopted a CRISPR-based genome editing approach to improve the efficiency of recombination in order to generate allelic isogenic HD models in human cells. Incorporation of a rapid antibody-based screening approach to measure recombination provides a powerful method to determine relative efficiency of genome editing for modeling polyglutamine diseases or understanding factors that modulate CRISPR/Cas9 HR.
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