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

Normal stem cells and cancer stem cells (CSCs) share similar properties,in that both have the capacity to self-renew and differentiate into multiple cell types. In both the normal stem cell and cancer stem cell fields,there has been a great need for a universal marker that can effectively identify and isolate these rare populations of cells in order to characterize them and use this information for research and therapeutic purposes. Currently,it would appear that certain isoenzymes of the aldehyde dehydrogenase (ALDH) superfamily may be able to fulfill this role as a marker for both normal and cancer stem cells. ALDH has been identified as an important enzyme in the protection of normal hematopoietic stem cells,and is now also widely used as a marker to identify and isolate various types of normal stem cells and CSCs. In addition,emerging evidence suggests that ALDH1 is not only a marker for stem cells,but may also play important functional roles related to self-protection,differentiation,and expansion. This comprehensive review discusses the role that ALDH plays in normal stem cells and CSCs,with focus on ALDH1 and ALDH3A1. Discrepancies in the functional themes between cell types and future perspectives for therapeutic applications will also be discussed. View Publication

Increasing evidence suggests that the deposition of amyloid plaques,composed primarily of the amyloid-beta protein (Abeta),within the cerebrovasculature is a frequent occurrence in Alzheimer's disease and may play a significant role in disease progression. Accordingly,the pathogenic mechanisms by which Abeta can alter vascular function may have therapeutic implications. Despite observations that Abeta elicits a number of physiological responses in endothelial cells,ranging from alteration of protein expression to cell death,the Abeta species accountable for these responses remains unexplored. In the current study,we show that isolated soluble Abeta aggregation intermediates activate human brain microvascular endothelial cells for both adhesion and subsequent transmigration of monocyte cells in the absence of endothelial cell death and monolayer disruption. In contrast,unaggregated Abeta monomer and mature Abeta fibril fail to induce any change in endothelial adhesion or transmigration. Correlations between average Abeta aggregate size and observed increases in adhesion illustrate that smaller soluble aggregates are more potent activators of endothelium. These results support previous studies demonstrating heightened neuronal activity of soluble Abeta aggregates,including Abeta-derived diffusible ligands,oligomers,and protofibrils,and further show that soluble aggregates also selectively exhibit activity in a vascular cell model. View Publication

For years,our ability to study pathological changes in neurological diseases has been hampered by the lack of relevant models until the recent groundbreaking work from Yamanaka's group showing that it is feasible to generate induced pluripotent stem cells (iPSCs) from human somatic cells and to redirect the fate of these iPSCs into differentiated cells. In particular,much interest has focused on the ability to differentiate human iPSCs into neuronal progenitors and functional neurons for relevance to a large number of pathologies including mental retardation and behavioral or degenerative syndromes. Current differentiation protocols are time-consuming and generate limited amounts of cells,hindering use on a large scale. We describe a feeder-free method relying on the use of a chemically defined medium that overcomes the need for embryoid body formation and neuronal rosette isolation for neuronal precursors and terminally differentiated neuron production. Four days after induction,expression of markers of the neurectoderm lineage is detectable. Between 4 and 7 days,neuronal precursors can be expanded,frozen,and thawed without loss of proliferation and differentiation capacities or further differentiated. Terminal differentiation into the different subtypes of mature neurons found in the human brain were observed. At 6-35 days after induction,cells express typical voltage-gated and ionotrophic receptors for GABA,glycine,and acetylcholine. This specific and efficient single-step strategy in a chemically defined medium allows the production of mature neurons in 20-40 days with multiple applications,especially for modeling human pathologies. View Publication

The ability to generate spiral ganglion neurons (SGNs) from stem cells is a necessary prerequisite for development of cell-replacement therapies for sensorineural hearing loss. We present a protocol that directs human embryonic stem cells (hESCs) toward a purified population of otic neuronal progenitors (ONPs) and SGN-like cells. Between 82% and 95% of these cells express SGN molecular markers,they preferentially extend neurites to the cochlear nucleus rather than nonauditory nuclei,and they generate action potentials. The protocol follows an in vitro stepwise recapitulation of developmental events inherent to normal differentiation of hESCs into SGNs,resulting in efficient sequential generation of nonneuronal ectoderm,preplacodal ectoderm,early prosensory ONPs,late ONPs,and cells with cellular and molecular characteristics of human SGNs. We thus describe the sequential signaling pathways that generate the early and later lineage species in the human SGN lineage,thereby better describing key developmental processes. The results indicate that our protocol generates cells that closely replicate the phenotypic characteristics of human SGNs,advancing the process of guiding hESCs to states serving inner-ear cell-replacement therapies and possible next-generation hybrid auditory prostheses. textcopyright Stem Cells Translational Medicine 2017;6:923-936. View Publication

Glioblastoma Multiforme (GBM) continues to have a poor patient prognosis despite optimal standard of care. Glioma stem cells (GSCs) have been implicated as the presumed cause of tumor recurrence and resistance to therapy. With this in mind,we screened a diverse chemical library of 2,000 compounds to identify therapeutic agents that inhibit GSC proliferation and therefore have the potential to extend patient survival. High-throughput screens (HTS) identified 78 compounds that repeatedly inhibited cellular proliferation,of which 47 are clinically approved for other indications and 31 are experimental drugs. Several compounds (such as digitoxin,deguelin,patulin and phenethyl caffeate) exhibited high cytotoxicity,with half maximal inhibitory concentrations (IC50) in the low nanomolar range. In particular,the FDA approved drug for the treatment of alcoholism,disulfiram (DSF),was significantly potent across multiple patient samples (IC50 of 31.1 nM). The activity of DSF was potentiated by copper (Cu),which markedly increased GSC death. DSF-Cu inhibited the chymotrypsin-like proteasomal activity in cultured GSCs,consistent with inactivation of the ubiquitin-proteasome pathway and the subsequent induction of tumor cell death. Given that DSF is a relatively non-toxic drug that can penetrate the blood-brain barrier,we suggest that DSF should be tested (as either a monotherapy or as an adjuvant) in pre-clinical models of human GBM. Data also support targeting of the ubiquitin-proteasome pathway as a therapeutic approach in the treatment of GBM. View Publication

PTEN is a tumour suppressor frequently mutated in many types of cancers. Here we show that targeted disruption of PTEN leads to neoplastic transformation of human neural stem cells (NSCs),but not mesenchymal stem cells. PTEN-deficient NSCs display neoplasm-associated metabolic and gene expression profiles and generate intracranial tumours in immunodeficient mice. PTEN is localized to the nucleus in NSCs,binds to the PAX7 promoter through association with cAMP responsive element binding protein 1 (CREB)/CREB binding protein (CBP) and inhibits PAX7 transcription. PTEN deficiency leads to the upregulation of PAX7,which in turn promotes oncogenic transformation of NSCs and instates 'aggressiveness' in human glioblastoma stem cells. In a large clinical database,we find increased PAX7 levels in PTEN-deficient glioblastoma. Furthermore,we identify that mitomycin C selectively triggers apoptosis in NSCs with PTEN deficiency. Together,we uncover a potential mechanism of how PTEN safeguards NSCs,and establish a cellular platform to identify factors involved in NSC transformation,potentially permitting personalized treatment of glioblastoma. View Publication

Amyotrophic lateral sclerosis is a progressive disease characterized by the loss of upper and lower motor neurons,leading to paralysis of voluntary muscles. About 10% of all ALS cases are familial (fALS),among which 15-20% are linked to Cu/Zn superoxide dismutase (SOD1) mutations,usually inherited in an autosomal dominant manner. To date only one FDA approved drug is available which increases survival moderately. Our understanding of ALS disease mechanisms is largely derived from rodent model studies,however due to the differences between rodents and humans,it is necessary to have humanized models for studies of disease pathogenesis as well as drug development. Therefore,we generated a comprehensive library of a total 22 of fALS patient-specific induced pluripotent stem cell (iPSC) lines. These cells were thoroughly characterized before being deposited into the library. The library of cells includes a variety of C9orf72 mutations,sod1 mutations,FUS,ANG and FIG4 mutations. Certain mutations are represented with more than one line,which allows for studies of variable genetic backgrounds. In addition,these iPSCs can be successfully differentiated to astroglia,a cell type known to play a critical role in ALS disease progression. This library represents a comprehensive resource that can be used for ALS disease modeling and the development of novel therapeutics. View Publication

We studied a new method of treatment of amyotrophic lateral sclerosis with autologous mesenchymal stem cells. Autologous mesenchymal stem cells were injected intravenously (intact cells) or via lumbar puncture (cells committed to neuronal differentiation). Evaluation of the results of cell therapy after 12-month follow-up revealed slowing down of the disease progression in 10 patients in comparison with the control group consisting of 15 patients. The cell therapy was safe for the patients. View Publication