搜索结果: 'methocult media formulations for mouse hematopoietic cells serum containing'

Tristetraprolin (TTP,Zfp36,Nup475,Tis11) dramatically reduces the stability of target mRNAs by binding to AU-rich elements in their 3' untranslated regions. Through this mechanism,TTP functions as a rheostatic,temporal regulator of gene expression. TTP knockout (KO) mice exhibit completely penetrant granulocytic hyperplasia. We have shown that the hematopoietic stem-progenitor cell compartment in TTP KO mice is also altered. Although no change was detected in long-term hematopoietic stem cell (HSC) frequency or function,as assayed by immunophenotypic markers or limiting dilution transplants,we observed increases in the frequencies and numbers of short-term HSCs,multipotent progenitors,and granulocyte-monocyte progenitors. This pattern is consistent with reactive granulopoiesis View Publication

Site-1 protease (S1P) ablation in the osterix-lineage in mice drastically reduces bone development and downregulates bone marrow-derived skeletal stem cells. Here we show that these mice also suffer from spina bifida occulta with a characteristic lack of bone fusion in the posterior neural arches. Molecular analysis of bone marrow-derived non-red blood cell cells,via single-cell RNA-Seq and protein mass spectrometry,demonstrate that these mice have a much-altered bone marrow with a significant increase in neutrophils and Ly6C-expressing leukocytes. The molecular composition of bone marrow neutrophils is also different as they express more and additional members of the stefin A (Stfa) family of proteins. In vitro,recombinant Stfa1 and Stfa2 proteins have the ability to drastically inhibit osteogenic differentiation of bone marrow stromal cells,with no effect on adipogenic differentiation. FACS analysis of hematopoietic stem cells show that despite a decrease in hematopoietic stem cells,S1P ablation results in an increased production of granulocyte-macrophage progenitors,the precursors to neutrophils. These observations indicate that S1P has a role in the lineage specification of hematopoietic stem cells and/or their progenitors for development of a normal hematopoietic niche. Our study designates a fundamental requirement of S1P for maintaining a balanced regenerative capacity of the bone marrow niche. View Publication

A promising and increasingly exploited property of hematopoietic stem cells is their ability to efflux the fluorescent dye Hoechst 33342. The Hoechst-negative cells are isolated by fluorescence-activated cell sorting as a so-called side population" (SP) of bone marrow. This SP from bone marrow View Publication

The aryl hydrocarbon receptor (AhR),a transcription factor known for mediating xenobiotic toxicity,is expressed in B cells,which are known targets for environmental pollutants. However,it is unclear what the physiological functions of AhR in B cells are. We show here that expression of Ahr in B cells is up-regulated upon B-cell receptor (BCR) engagement and IL-4 treatment. Addition of a natural ligand of AhR,FICZ,induces AhR translocation to the nucleus and transcription of the AhR target gene Cyp1a1,showing that the AhR pathway is functional in B cells. AhR-deficient (Ahr(-/-)) B cells proliferate less than AhR-sufficient (Ahr(+/+)) cells following in vitro BCR stimulation and in vivo adoptive transfer models confirmed that Ahr(-/-) B cells are outcompeted by Ahr(+/+) cells. Transcriptome comparison of AhR-deficient and AhR-sufficient B cells identified cyclin O (Ccno),a direct target of AhR,as a top candidate affected by AhR deficiency. View Publication

To address existing limitations in live neuron imaging,we have developed NeuO,a novel cell-permeable fluorescent probe with an unprecedented ability to label and image live neurons selectively over other cells in the brain. NeuO enables robust live neuron imaging and isolation in vivo and in vitro across species; its versatility and ease of use sets the basis for its development in a myriad of neuronal targeting applications. View Publication

The slow kinetics and low efficiency of reprogramming methods to generate human induced pluripotent stem cells (iPSCs) impose major limitations on their utility in biomedical applications. Here we describe a chemical approach that dramatically improves (200-fold) the efficiency of iPSC generation from human fibroblasts,within seven days of treatment. This will provide a basis for developing safer,more efficient,nonviral methods for reprogramming human somatic cells. View Publication

Unlocking the clinical potential of stem cell based therapies requires firstly elucidation of the biological mechanisms which direct stem cell fate decisions and thereafter,technical advances which allow these processes to be driven in a fully defined culture environment. Strategies for the generation of defined surfaces for human embryonic stem cell (hESC) and mesenchymal stem cell (MSC) culture remain in their infancy. In this paper we outline a simple,effective and efficient method for presenting proteins or peptides on an otherwise non-fouling Layer-by-Layer (LbL) self-assembled surface of hyaluronic acid (HA) and chitosan (CHI). We are able to generate a surface that has both good temporal stability and the ability to direct biological outcomes based on its defined surface composition. Surface functionalization is achieved through suspending the selected extracellular matrix (ECM) protein domain or extracted full-length protein in buffer containing a cross-linking agent (N-hydroxysulfosuccinimide/N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride) over the LbL HA-CHI surface and then allowing the solvent to evaporate overnight. This simple,but important step results in remarkable protein deposition efficiencies often exceeding 50%,whereas traditional cross-linking methods result in such poor deposition of non-collagenous proteins that a.) quantification of bound amounts of protein is outside the resolution of commonly utilized protein assays,and b.) these surfaces are both unable to support cell attachment and growth. The utility of the protein-modified HA-CHI surfaces is demonstrated through the identification of specific hESC attachment efficiencies and through directing MSC osteogenic outcomes on these fully defined surfaces. This simple and scalable method is shown to enable the development of defined stem cell culture conditions,as well as the elucidation of the fundamental biological processes necessary for the realization of stem cell based therapies. View Publication