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

The human induced pluripotent stem cell (hiPSC) provides a breakthrough approach that helps overcoming ethical and allergenic challenges posed in application of neural stem cells (NSCs) in targeted cancer gene therapy. However,the tumor-tropic capacity of hiPSC-derived NSCs (hiPS-NSCs) still has much room to improve. Here we attempted to promote the tumor tropism of hiPS-NSCs by manipulating the activity of endogenous miR-199a/214 cluster that is involved in regulation of hypoxia-stimulated cell migration. We first developed a baculovirus-delivered CRISPR interference (CRISPRi) system that sterically blocked the E-box element in the promoter of the miR-199a/214 cluster with an RNA-guided catalytically dead Cas9 (dCas9). We then applied this CRISPRi system to hiPS-NSCs and successfully suppressed the expression of miR-199a-5p,miR-199a-3p,and miR-214 in the microRNA gene cluster. Meanwhile,the expression levels of their targets related to regulation of hypoxia-stimulated cell migration,such as HIF1A,MET,and MAPK1,were upregulated. Further migration assays demonstrated that the targeted inhibition of the miR-199a/214 cluster significantly enhanced the tumor tropism of hiPS-NSCs both in vitro and in vivo. These findings suggest a novel application of CRISPRi in NSC-based tumor-targeted gene therapy. View Publication

The incidence of cardiovascular disease represents a significant and growing health-care challenge to the developed and developing world. The ability of native heart muscle to regenerate in response to myocardial infarct is minimal. Tissue engineering and regenerative medicine approaches represent one promising response to this difficulty. Here,we present methods for the construction of a cell-seeded cardiac patch with the potential to promote regenerative outcomes in heart muscle with damage secondary to myocardial infarct. This method leverages iPS cells and a fibrin-based scaffold to create a simple and commercially viable tissue-engineered cardiac patch. Human-induced pluripotent stem cells (hiPSCs) can,in principle,be differentiated into cells of any lineage. However,most of the protocols used to generate hiPSC-derived endothelial cells (ECs) and cardiomyocytes (CMs) are unsatisfactory because the yield and phenotypic stability of the hiPSC-ECs are low,and the hiPSC-CMs are often purified via selection for expression of a promoter-reporter construct. In this chapter,we describe an hiPSC-EC differentiation protocol that generates large numbers of stable ECs and an hiPSC-CM differentiation protocol that does not require genetic manipulation,single-cell selection,or sorting with fluorescent dyes or other reagents. We also provide a simple but effective method that can be used to combine hiPSC-ECs and hiPSC-CMs with hiPSC-derived smooth muscle cells to engineer a contracting patch of cardiac cells. View Publication

Pancreatic ductal adenocarcinoma (PDA) is an aggressive malignancy with one of the worst outcomes among all cancers. PDA often recurs after initial treatment to result in patient death despite the use of chemotherapy or radiation therapy. PDA contains a subset of tumor-initiating cells capable of extensive self-renewal known as cancer stem cells (CSC),which may contribute to therapeutic resistance and metastasis. At present,conventional chemotherapy and radiotherapy are largely ineffective in depleting CSC pool,suggesting the need for novel therapies that specifically target the cancer-sustaining stem cells for tumor eradication and to improve the poor prognosis of PDA patients. In this study,we report that death receptor 5 (DR5) is enriched in pancreatic CSCs compared with the bulk of the tumor cells. Treating a collection of freshly generated patient-derived PDA xenografts with gemcitabine,the first-line chemotherapeutic agent for PDA,is initially effective in reducing tumor size,but largely ineffective in diminishing the CSC populations,and eventually culminated in tumor relapse. However,a combination of tigatuzumab,a fully humanized DR5 agonist monoclonal antibody,with gemcitabine proved to be more efficacious by providing a double hit to kill both CSCs and bulk tumor cells. The combination therapy produced remarkable reduction in pancreatic CSCs,tumor remissions,and significant improvements in time to tumor progression in a model that is considered more difficult to treat. These data provide the rationale to explore the DR5-directed therapies in combination with chemotherapy as a therapeutic option to improve the current standard of care for pancreatic cancer patients. View Publication

All trans-retinoic acid (ATRA) is widely used to direct the differentiation of cultured stem cells. When exposed to the pluripotent human embryonal carcinoma (EC) stem cell line,TERA2.cl.SP12,ATRA induces ectoderm differentiation and the formation of neuronal cell types. We have previously generated synthetic analogues of retinoic acid (EC23 and EC19) which also induce the differentiation of EC cells. Even though EC23 and EC19 have similar chemical structures,they have differing biochemical effects in terms of EC cell differentiation. EC23 induces neuronal differentiation in a manner similar to ATRA,whereas EC19 directs the cells to form epithelial-like derivatives. Previous MALDI-TOF MS analysis examined the response of TERA2.cl.SP12 cells after exposure to ATRA,EC23 and EC19 and further demonstrated the similarly in the effect of ATRA and EC23 activity whilst responses to EC19 were very different. In this study,we show that Fourier Transform Infrared Micro-Spectroscopy (FT-IRMS) coupled with appropriate scatter correction and multivariate analysis can be used as an effective tool to further investigate the differentiation of human pluripotent stem cells and monitor the alternative affects different retinoid compounds have on the induction of differentiation. FT-IRMS detected differences between cell populations as early as 3 days of compound treatment. Populations of cells treated with different retinoid compounds could easily be distinguished from one another during the early stages of cell differentiation. These data demonstrate that FT-IRMS technology can be used as a sensitive screening technique to monitor the status of the stem cell phenotype and progression of differentiation along alternative pathways in response to different compounds. View Publication

Human rhinovirus (HRV)-induced respiratory infections are associated with elevated levels of IFN-gamma-inducible protein 10 (IP-10),which is an enhancer of T lymphocyte chemotaxis and correlates with symptom severity and T lymphocyte number. Increased IP-10 expression is exhibited by airway epithelial cells following ex vivo HRV challenge and requires intracellular viral replication; however,there are conflicting reports regarding the necessity of type I IFN receptor ligation for IP-10 expression. Furthermore,the involvement of resident airway immune cells,predominantly bronchoalveolar macrophages,in contributing to HRV-stimulated IP-10 elaboration remains unclear. In this regard,our findings demonstrate that ex vivo exposure of human peripheral blood monocytes and bronchoalveolar macrophages (monocytic cells) to native or replication-defective HRV serotype 16 (HRV16) resulted in similarly robust levels of IP-10 release,which occurred in a time- and dose-dependent manner. Furthermore,HRV16 induced a significant increase in type I IFN (IFN-alpha) release and STAT1 phosphorylation in monocytes. Neutralization of the type I IFN receptor and inhibition of JAK or p38 kinase activity strongly attenuated HRV16-stimulated STAT1 phosphorylation and IP-10 release. Thus,this work supports a model,wherein HRV16-induced IP-10 release by monocytic cells is modulated via autocrine/paracrine action of type I IFNs and subsequent JAK/STAT pathway activity. Our findings demonstrating robust activation of monocytic cells in response to native and/or replication-defective HRV16 challenge represent the first evidence indicating a mechanistic disparity in the activation of macrophages when compared with epithelial cells and suggest that macrophages likely contribute to cytokine elaboration following HRV challenge in vivo. View Publication

Using live-cell microscopy,we find that loss of VPS13C in human neurons disrupts lysosomal morphology and dynamics with increased inter-lysosomal tethers,leading to impaired lysosomal motility and defective lysosomal function as well as a decreased phospho-Rab10-mediated lysosomal stress response. Loss-of-function mutations in VPS13C are linked to early-onset Parkinson’s disease (PD). While VPS13C has been previously studied in non-neuronal cells,the neuronal role of VPS13C in disease-relevant human dopaminergic neurons has not been elucidated. Using live-cell microscopy,we investigated the role of VPS13C in regulating lysosomal dynamics and function in human iPSC-derived dopaminergic neurons. Loss of VPS13C in dopaminergic neurons disrupts lysosomal morphology and dynamics with increased inter-lysosomal contacts,leading to impaired lysosomal motility and cellular distribution,as well as defective lysosomal hydrolytic activity and acidification. We identified Rab10 as a phospho-dependent interactor of VPS13C on lysosomes and observed a decreased phospho-Rab10-mediated lysosomal stress response upon loss of VPS13C. These findings highlight an important role of VPS13C in regulating lysosomal homeostasis in human dopaminergic neurons and suggest that disruptions in Rab10-mediated lysosomal stress response contribute to disease pathogenesis in VPS13C-linked PD. View Publication

There is a medical need for an agent with the positive effects of estrogen on bone and the cardiovascular system,but without the negative effects on reproductive tissue. Raloxifene (LY139481 HCI) is a benzothiophene derivative that binds to the estrogen receptor and inhibits the effects of estrogen on the uterus. In an ovariectomized (OVX) rat model we investigated the effects of raloxifene on bone loss (induced by estrogen deficiency),serum lipids,and uterine tissue. After oral administration of raloxifene for 5 wk (0.1-10 mg/kg per d) to OVX rats,bone mineral density in the distal femur and proximal tibia was significantly greater than that observed in OVX controls (ED50 of 0.03-0.3 mg/kg). Serum cholesterol was lower in the raloxifene-treated animals,which had a minimal effective dose of 0.1 mg/kg and an approximate oral ED50 of 0.2 mg/kg. The effects of raloxifene on bone and serum cholesterol were comparable to those of a 0.1-mg/kg per d oral dose of ethynyl estradiol. Raloxifene diverged dramatically from estrogen in its lack of significant estrogenic effects on uterine tissue. Ethynyl estradiol produced a marked elevation in a number of uterine histologic parameters (e.g.,epithelial cell height,stromal eosinophilia). These data suggest that raloxifene has promise as an agent with beneficial bone and cardiovascular effects in the absence of significant uterine effects. View Publication

STAT3 is constitutively activated in many cancer types,including lung cancer,and can induce cancer cell proliferation and cancer stem cell (CSC) maintenance. STAT3 is activated by tyrosine kinases,such as JAK and SRC,but the mechanism by which STAT3 maintains its activated state in cancer cells remains unclear. Here,we show that PRMT5 directly methylates STAT3 and enhances its activated tyrosine phosphorylation in non-small cell lung cancer (NSCLC) cells. PRMT5 expression is also induced by STAT3,suggesting the presence of a positive feedback loop in cancer cells. Furthermore,methylation of STAT3 at arginine 609 by PRMT5 is important for its transcriptional activity and support of tumour growth and CSC maintenance. Indeed,NSCLC cells expressing the STAT3 mutant which R609 was replaced to alanine (R609K) show significantly impaired tumour growth in nude mice. Overall,our study reveals a mechanism by which STAT3 remains activated in NSCLC and provides a new target for cancer therapeutic approaches. Subject terms: Oncogenes,Non-small-cell lung cancer,Growth factor signalling View Publication

Carbonic anhydrases (CAs) comprise a family of zinc-containing enzymes that catalyze the reversible hydration of carbon dioxide. CAs contribute to a myriad of physiological processes,including pH regulation,anion transport and water balance. To date,16 known members of the mammalian alpha-CA family have been identified. Given that the catalytic family members share identical reaction chemistry,their physiologic roles are influenced greatly by their tissue and sub-cellular locations. CAVI is the lone secreted CA and exists in both saliva and the gastrointestinal mucosa. An alternative,stress-inducible isoform of CAVI (CAVI-b) has been shown to be expressed from a cryptic promoter that is activated by the CCAAT/Enhancer-Binding Protein Homologous Protein (CHOP). The CAVI-b isoform is not secreted and is currently of unknown physiological function. Here we use neuronal models,including a model derived using Car6 and CHOP gene ablations,to delineate a role for CAVI-b in ischemic protection. Our results demonstrate that CAVI-b expression,which is increased through CHOP-signaling in response to unfolded protein stress,is also increased by oxygen-glucose deprivation (OGD). While enforced expression of CAVI-b is not sufficient to protect against ischemia,CHOP regulation of CAVI-b is necessary for adaptive changes mediated by BDNF that reduce subsequent ischemic damage. These results suggest that CAVI-b comprises a necessary component of a larger adaptive signaling pathway downstream of CHOP. View Publication