Ioannidis P et al. (MAY 2005)
The Journal of biological chemistry 280 20 20086--93
CRD-BP/IMP1 expression characterizes cord blood CD34+ stem cells and affects c-myc and IGF-II expression in MCF-7 cancer cells.
The coding region determinant-binding protein/insulin-like growth factor II mRNA-binding protein (CRD-BP/IMP1) is an RNA-binding protein specifically recognizing c-myc,leader 3' IGF-II and tau mRNAs,and the H19 RNA. CRD-BP/IMP1 is predominantly expressed in embryonal tissues but is de novo activated and/or overexpressed in various human neoplasias. To address the question of whether CRD-BP/IMP1 expression characterizes certain cell types displaying distinct proliferation and/or differentiation properties (i.e. stem cells),we isolated cell subpopulations from human bone marrow,mobilized peripheral blood,and cord blood,all sources known to contain stem cells,and monitored for its expression. CRD-BP/IMP1 was detected only in cord blood-derived CD34(+) stem cells and not in any other cell type of either adult or cord blood origin. Adult BM CD34(+) cells cultured in the presence of 5'-azacytidine expressed de novo CRD-BP/IMP1,suggesting that epigenetic modifications may be responsible for its silencing in adult non-expressing cells. Furthermore,by applying the short interfering RNA methodology in MCF-7 cells,we observed,subsequent to knocking down CRD-BP/IMP1,decreased c-myc expression,increased IGF-II mRNA levels,and reduced cell proliferation rates. These data 1) suggest a normal role for CRD-BP/IMP1 in pluripotent stem cells with high renewal capacity,like the CB CD34(+) cells,2) indicate that altered methylation may directly or indirectly affect its expression in adult cells,3) imply that its de novo activation in cancer cells may affect the expression of c-Myc and insulin-like growth factor II,and 4) indicate that the inhibition of CRD-BP/IMP1 expression might affect cancer cell proliferation.
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Chen S et al. (JAN 2004)
Journal of the American Chemical Society 126 2 410--1
Dedifferentiation of lineage-committed cells by a small molecule.
Combinatorial libraries were screened for molecules that induce mouse myogenic lineage committed cells to dedifferentiate in vitro. A 2,6-disubstituted purine,reversine,was discovered that induces lineage reversal of C2C12 cells to become multipotent progenitor cells which can redifferentiate into osteoblasts and adipocytes. This and other such molecules are likely to provide new insights into the molecular mechanisms that control cellular dedifferentiation and may ultimately be useful to in vivo stem cell biology and therapy.
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产品类型：
产品号#：
72612
72614
产品名：
Reversine
逆转素（Reversine）
Perez JE et al. (FEB 2017)
Nanotechnology 28 5 55703
Mesenchymal stem cells cultured on magnetic nanowire substrates.
Stem cells have been shown to respond to extracellular mechanical stimuli by regulating their fate through the activation of specific signaling pathways. In this work,an array of iron nanowires (NWs) aligned perpendicularly to the surface was fabricated by pulsed electrodepositon in porous alumina templates followed by a partial removal of the alumina to reveal 2-3 μm of the NWs. This resulted in alumina substrates with densely arranged NWs of 33 nm in diameter separated by 100 nm. The substrates were characterized by scanning electron microscopy (SEM) energy dispersive x-ray analysis and vibrating sample magnetometer. The NW array was then used as a platform for the culture of human mesenchymal stem cells (hMSCs). The cells were stained for the cell nucleus and actin filaments,as well as immuno-stained for the focal adhesion protein vinculin,and then observed by fluorescence microscopy in order to characterize their spreading behavior. Calcein AM/ethidium homodimer-1 staining allowed the determination of cell viability. The interface between the cells and the NWs was studied using SEM. Results showed that hMSCs underwent a re-organization of actin filaments that translated into a change from an elongated to a spherical cell shape. Actin filaments and vinculin accumulated in bundles,suggesting the attachment and formation of focal adhesion points of the cells on the NWs. Though the overall number of cells attached on the NWs was lower compared to the control,the attached cells maintained a high viability (>90%) for up to 6 d. Analysis of the interface between the NWs and the cells confirmed the re-organization of F-actin and revealed the adhesion points of the cells on the NWs. Additionally,a net of filopodia surrounded each cell,suggesting the probing of the array to find additional adhesion points. The cells maintained their round shape for up to 6 d of culture. Overall,the NW array is a promising nanostructured platform for studying and influencing hMSCs differentiation.
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产品类型：
产品号#：
70022
70071
产品名：
Chen S et al. (JUN 2007)
Proceedings of the National Academy of Sciences of the United States of America 104 25 10482--7
Reversine increases the plasticity of lineage-committed mammalian cells.
Previously,a small molecule,reversine,was identified that reverses lineage-committed murine myoblasts to a more primitive multipotent state. Here,we show that reversine can increase the plasticity of C2C12 myoblasts at the single-cell level and that reversine-treated cells gain the ability to differentiate into osteoblasts and adipocytes under lineage-specific inducing conditions. Moreover,reversine is active in multiple cell types,including 3T3E1 osteoblasts and human primary skeletal myoblasts. Biochemical and cellular experiments suggest that reversine functions as a dual inhibitor of nonmuscle myosin II heavy chain and MEK1,and that both activities are required for reversine's effect. Inhibition of MEK1 and nonmuscle myosin II heavy chain results in altered cell cycle and changes in histone acetylation status,but other factors also may contribute to the activity of reversine,including activation of the PI3K signaling pathway.
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产品类型：
产品号#：
72612
72614
产品名：
Reversine
逆转素（Reversine）
Bhattacharyya S and Khanduja KL (APR 2010)
Acta biochimica et biophysica Sinica 42 4 237--42
New hope in the horizon: cancer stem cells.
The major goal of researchers and oncologists is to develop promising ground for novel therapeutic strategies to prevent recurrence or relapse of cancer. Recent evidences suggest that a subset of cells called cancer stem cells (CSCs) are present within the tumor mass which possess tumorigenic capacity and may be responsible for propagation,relapse,and metastatic dissemination. These cells have certain stem cell-like properties,e.g. quiescence,selfrenewal,asymmetric division,and multidrug resistance which allow them to drive tumor growth and evade conventional therapies. A number of markers and assays have been designed to isolate and characterize the CSC population from the bulk tumor. The objective now is to selectively target the CSCs in order to eliminate the tumor from root,overcoming the emergence of clones capable of evading traditional therapy. This approach may help in increasing the overall disease-free survival in some cancers.
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产品类型：
产品号#：
01700
01705
01702
产品名：
ALDEFLUOR™ 试剂盒
ALDEFLUOR™ DEAB试剂
ALDEFLUOR™测定缓冲液
Moore JJC et al. (JAN 2010)
Stem Cell Research & Therapy 1 3 23
Efficient, high-throughput transfection of human embryonic stem cells.
Genetic manipulation of human embryonic stem cells (hESC) has been limited by their general resistance to common methods used to introduce exogenous DNA or RNA. Efficient and high throughput transfection of nucleic acids into hESC would be a valuable experimental tool to manipulate these cells for research and clinical applications. We investigated the ability of two commercially available electroporation systems,the Nucleofection® 96-well Shuttle® System from Lonza and the Neon™ Transfection System from Invitrogen to efficiently transfect hESC. Transfection efficiency was measured by flow cytometry for the expression of the green fluorescent protein and the viability of the transfected cells was determined by an ATP catalyzed luciferase reaction. The transfected cells were also analyzed by flow cytometry for common markers of pluripotency. Both systems are capable of transfecting hESC at high efficiencies with little loss of cell viability. However,the reproducibility and the ease of scaling for high throughput applications led us to perform more comprehensive tests on the Nucleofection® 96-well Shuttle® System. We demonstrate that this method yields a large fraction of transiently transfected cells with minimal loss of cell viability and pluripotency,producing protein expression from plasmid vectors in several different hESC lines. The method scales to a 96-well plate with similar transfection efficiencies at the start and end of the plate. We also investigated the efficiency with which stable transfectants can be generated and recovered under antibiotic selection. Finally,we found that this method is effective in the delivery of short synthetic RNA oligonucleotides (siRNA) into hESC for knockdown of translation activity via RNA interference. Our results indicate that these electroporation methods provide a reliable,efficient,and high-throughput approach to the genetic manipulation of hESC.
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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
Wu X et al. (JAN 2018)
Cell 172 3 423--438.e25
Intrinsic Immunity Shapes Viral Resistance of Stem Cells.
Stem cells are highly resistant to viral infection compared to their differentiated progeny; however,the mechanism is mysterious. Here,we analyzed gene expression in mammalian stem cells and cells at various stages of differentiation. We find that,conserved across species,stem cells express a subset of genes previously classified as interferon (IFN) stimulated genes (ISGs) but that expression is intrinsic,as stem cells are refractory to interferon. This intrinsic ISG expression varies in a cell-type-specific manner,and many ISGs decrease upon differentiation,at which time cells become IFN responsive,allowing induction of a broad spectrum of ISGs by IFN signaling. Importantly,we show that intrinsically expressed ISGs protect stem cells against viral infection. We demonstrate the in vivo importance of intrinsic ISG expression for protecting stem cells and their differentiation potential during viral infection. These findings have intriguing implications for understanding stem cell biology and the evolution of pathogen resistance.
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Zhou T et al. (JUL 2011)
Journal of the American Society of Nephrology : JASN 22 7 1221--1228
Generation of induced pluripotent stem cells from urine
Forced expression of selected transcription factors can transform somatic cells into embryonic stem cell (ESC)-like cells,termed induced pluripotent stem cells (iPSCs). There is no consensus regarding the preferred tissue from which to harvest donor cells for reprogramming into iPSCs,and some donor cell types may be more prone than others to accumulation of epigenetic imprints and somatic cell mutations. Here,we present a simple,reproducible,noninvasive method for generating human iPSCs from renal tubular cells present in urine. This procedure eliminates many problems associated with other protocols,and the resulting iPSCs display an excellent ability to differentiate. These data suggest that urine may be a preferred source for generating iPSCs.
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Naive embryonic stem cells hold great promise for research and therapeutics as they have broad and robust developmental potential. While such cells are readily derived from mouse blastocysts it has not been possible to isolate human equivalents easily,although human naive-like cells have been artificially generated (rather than extracted) by coercion of human primed embryonic stem cells by modifying culture conditions or through transgenic modification. Here we show that a sub-population within cultures of human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) manifests key properties of naive state cells. These naive-like cells can be genetically tagged,and are associated with elevated transcription of HERVH,a primate-specific endogenous retrovirus. HERVH elements provide functional binding sites for a combination of naive pluripotency transcription factors,including LBP9,recently recognized as relevant to naivety in mice. LBP9-HERVH drives hESC-specific alternative and chimaeric transcripts,including pluripotency-modulating long non-coding RNAs. Disruption of LBP9,HERVH and HERVH-derived transcripts compromises self-renewal. These observations define HERVH expression as a hallmark of naive-like hESCs,and establish novel primate-specific transcriptional circuitry regulating pluripotency.
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EasySep™小鼠TIL（CD45）正选试剂盒
研究综述Neural Stem Cells: Identification, Function, Culture, and Isolation
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