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

In stem cell biology,a long-held structure–function relationship is the domed colony morphology and naïve pluripotency for mouse or human pluripotent stem cells. This link has provided a convenient way to recognize bona fide naïve pluripotent cells during derivation,passaging and characterization. However,the molecular basis of this link remains poorly understood. Results: We show that a loss of domed morphology may not impact the overall genetic architecture of naïve pluripotency in mouse embryonic stem cells (mESCs). We first generated stable mESC lines by knocking out Myh9 that encodes non-muscle myosin heavy chain IIA,resulting in colonies deprived of the typical domed morphology,but competent to differentiate into the three germ layers and chimeric mice. Modulating cell morphologies with inhibitors against kinases known to regulate myosin pathway also phenocopy the knockout in wild type mESCs. Conclusions: These results provide evidence that the domed morphology and potency can be uncoupled and suggest that domed structure is not a pre-requisite for acquiring and maintaining naïve pluripotency. View Publication

It is likely that arrhythmias should be avoided for therapies based on human pluripotent stem cell (hPSC)-derived cardiomyocytes (CM) to be effective. Towards achieving this goal,we introduced light-activated channelrhodopsin-2 (ChR2),a cation channel activated with 480 nm light,into human embryonic stem cells (hESC). By using in vitro approaches,hESC-CM are able to be activated with light. ChR2 is stably transduced into undifferentiated hESC via a lentiviral vector. Via directed differentiation,hESCChR2-CM are produced and subjected to optical stimulation. hESCChR2-CM respond to traditional electrical stimulation and produce similar contractility features as their wild-type counterparts but only hESCChR2-CM can be activated by optical stimulation. Here it is shown that a light sensitive protein can enable in vitro optical control of hESC-CM and that this activation occurs optimally above specific light stimulation intensity and pulse width thresholds. For future therapy,in vivo optical stimulation along with optical inhibition could allow for acute synchronization of implanted hPSC-CM with patient cardiac rhythms. View Publication

To build in vitro tissues for therapeutic applications,it is essential to replicate the spatial distribution of cells that occurs during morphogenesis in vivo. However,it remains technically challenging to simultaneously regulate the geometric alignment and aggregation of cells during tissue fabrication. Here,we introduce the acoustofluidic bioassembly induced morphogenesis,which is the combination of precise arrangement of cells by the mechanical forces produced by acoustofluidic cues,and the morphological and functional changes of cells in the following in vitro and in vivo cultures. The acoustofluidic bioassembly can be used to create tissues with regulated nano-,micro-,and macro-structures. We demonstrate that the neuromuscular tissue fabricated with the acoustofluidic bioassembly exhibits enhanced contraction dynamics,electrophysiology,and therapeutic efficacy. The potential of the acoustofluidic bioassembly as an in situ application is demonstrated by fabricating artificial tissues at the defect sites of living tissues. The acoustofluidic bioassembly induced morphogenesis can provide a pioneering platform to fabricate tissues for biomedical applications. Tissue engineering is essential for drug screening and regenerative medicine. Here,authors developed an acoustofluidic method that can induce morphogenesis of therapeutic tissues at varied dimensions/scales. View Publication

Expression of Mpl is restricted to hematopoietic cells in the megakaryocyte lineage and to undifferentiated progenitors,where it initiates critical cell survival and proliferation signals after stimulation by its ligand,thrombopoietin (TPO). As a result,a deficiency in Mpl function in patients with congenital amegakaryocytic thrombocytopenia (CAMT) and in mpl(-/-) mice produces profound thrombocytopenia and a severe stem cell-repopulating defect. Gene therapy has the potential to correct the hematopoietic defects of CAMT by ectopic gene expression that restores normal Mpl receptor activity. We rescued the mpl(-/-) mouse with a transgenic vector expressing mpl from the promoter elements of the 2-kb region of DNA just proximal to the natural gene start site. Transgene rescued mice exhibit thrombocytosis but only partial correction of the stem cell defect. Furthermore,they show very low-level expression of Mpl on platelets and megakaryocytes,and the transgene-rescued megakaryocytes exhibit diminished TPO-dependent kinase phosphorylation and reduced platelet production in bone marrow chimeras. Thrombocytosis is an unexpected consequence of reduced Mpl expression and activity. However,impaired TPO homeostasis in the transgene-rescued mice produces elevated plasma TPO levels,which serves as an unchecked stimulus to drive the observed excessive megakaryocytopoiesis. View Publication

Cancer-associated IDH mutations are characterized by neomorphic enzyme activity and resultant 2-hydroxyglutarate (2HG) production. Mutational and epigenetic profiling of a large acute myeloid leukemia (AML) patient cohort revealed that IDH1/2-mutant AMLs display global DNA hypermethylation and a specific hypermethylation signature. Furthermore,expression of 2HG-producing IDH alleles in cells induced global DNA hypermethylation. In the AML cohort,IDH1/2 mutations were mutually exclusive with mutations in the α-ketoglutarate-dependent enzyme TET2,and TET2 loss-of-function mutations were associated with similar epigenetic defects as IDH1/2 mutants. Consistent with these genetic and epigenetic data,expression of IDH mutants impaired TET2 catalytic function in cells. Finally,either expression of mutant IDH1/2 or Tet2 depletion impaired hematopoietic differentiation and increased stem/progenitor cell marker expression,suggesting a shared proleukemogenic effect. View Publication

A cDNA clone encoding a novel hematopoietic growth factor activity produced by a gibbon T cell line has been identified using a mammalian cell expression cloning system. The sequence of this cDNA proved to have significant homology to the sequence encoding murine interleukin 3 (IL-3). The human gene,which was readily identified because of its high degree of homology to the gibbon sequence,also displayed significant homology with the murine IL-3 sequence. The recombinant gibbon IL-3 protein proved to have multipotent colony stimulating activity when tested with normal human bone marrow cells,proving that this primate hematopoietin is not only structurally but also functionally related to murine IL-3. View Publication

Stimulating erythropoiesis is essential in the treatment of various types of anemia. Sheng Xue Ning (SXN) is commonly used in China as an iron supplement to treat iron deficiency anemia,renal anemia,and anemia in pregnancy. This research reports a novel effect of SXN in enhancing the proliferation of hematopoietic stem/progenitor cell (HSPC) to promote erythropoiesis in the bone marrow,which is distinct from conventional iron supplements that primarily aid in the maturation of red blood cells. Employing a model of hematopoietic dysfunction induced by X-ray exposure,we evaluated the efficacy of SXN in restoring hematopoietic function. SXN significantly promoted the recovery of peripheral erythroid cells and enhanced the proliferation and differentiation of Lin − /c-KIT + /Sca-1 + HSPC in mice exposed to X-ray irradiation. Our results showed that SXN elevated the expression of stem cell factor (SCF) and activated the SCF/c-KIT/PI3K/AKT signaling pathway,facilitating the proliferation and differentiation of HSPC. In vitro,SXN markedly enhanced the proliferation of bone marrow nucleated cell (BMNC) and the colony-forming capacity of BFU-E,CFU-E,and CFU-GM,while also elevating the expression of proteins involved in the SCF/c-KIT/PI3K/AKT pathway in BMNC. Additionally,SXN enhanced the proliferation and differentiation of mesenchymal stem cell (MSC) and increased SCF secretion. In conclusion,SXN demonstrates the capacity to enhance erythropoiesis by upregulating SCF expression,thereby promoting HSPC proliferation and differentiation via the SCF/c-KIT/PI3K/AKT pathway. SXN may offer a new strategy for improving the activity of HSPC and promoting erythropoiesis in the treatment of hematopoiesis disorders. View Publication