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

Understanding the molecular mechanisms that underlie neurodegenerative disorders has been hampered by a lack of readily available model systems that replicate the complexity of the human disease. Recent advances in stem cell technology have facilitated the derivation of patient-specific stem cells from a variety of differentiated cell types. These induced pluripotent stem cells (iPSCs) are attractive disease models since they can be grown and differentiated to produce large numbers of disease-relevant cell types. However,most iPSC lines are derived in advance of,and without the benefit of,neuropathological confirmation of the donor - the gold standard for many disease classifications and measurement of disease severity. While others have reported the generation of autopsy-confirmed iPSC lines from patient explants,these methods require outgrowth of cadaver tissue,which require additional time and is often only successul 50% of the time. Here we report the rapid generation of autopsy-confirmed iPSC lines from peripheral blood mononuclear cells (PBMCs) drawn postmortem. Since this approach doesn't require the propagation of previously frozen cadaver tissue,iPSC can be rapidly and efficiently produced from patients with autopsy-confirmed pathology. These matched iPSC-derived patient-specific neurons and postmortem brain tissue will support studies of specific mechanisms that drive the pathogenesis of neurodegenerative diseases. View Publication

The cancer stem cell (CSC) model suggests that a subpopulation of cells within the tumor,the CSCs,is responsible for cancer relapse and metastasis formation. CSCs hold unique characteristics,such as self-renewal,differentiation abilities,and resistance to chemotherapy,raising the need for discovering drugs that target CSCs. Previously we have found that the antihypertensive drug spironolactone impairs DNA damage response in cancer cells. Here we show that spironolactone,apart from inhibiting cancerous cell growth,is also highly toxic to CSCs. Notably,we demonstrate that CSCs have high basal levels of DNA double-strand breaks (DSBs). Mechanistically,we reveal that spironolactone does not damage the DNA but impairs DSB repair and induces apoptosis in cancer cells and CSCs while sparing healthy cells. In vivo,spironolactone treatment reduced the size and CSC content of tumors. Overall,we suggest spironolactone as an anticancer reagent,toxic to both cancer cells and,particularly to,CSCs. View Publication

Fatty-acid-binding proteins (FABPs) are key intracellular molecules involved in the uptake,transportation and storage of fatty acids and in the mediation of signal transduction and gene transcription. However,little is known regarding their expression and function in the oligodendrocyte lineage. We evaluate the in vivo and in vitro expression of FABP5 and FABP7 in oligodendrocyte lineage cells in the cortex and corpus callosum of adult mice,mixed cortical culture and oligosphere culture by immunofluorescent counter-staining with major oligodendrocyte lineage markers. In all settings,FABP7 expression was detected in NG2(+)/PDGFRα(+) oligodendrocyte progenitor cells (OPCs) that did not express FABP5. FABP5 was detected in mature CC1(+)/MBP(+) oligodendrocytes that did not express FABP7. Analysis of cultured OPCs showed a significant decrease in the population of FABP7-knockout (KO) OPCs and their BrdU uptake compared with wild-type (WT) OPCs. Upon incubation of OPCs in oligodendrocyte differentiation medium,a significantly lower percentage of FABP7-KO OPCs differentiated into O4(+) oligodendrocytes. The percentage of mature MBP(+) oligodendrocytes relative to whole O4(+)/MBP(+) oligodendrocytes was significantly lower in FABP7-KO and FABP5-KO than in WT cell populations. The percentage of terminally mature oligodendrocytes with membrane sheet morphology was significantly lower in FABP5-KO compared with WT cell populations. Thus,FABP7 and FABP5 are differentially expressed in oligodendrocyte lineage cells and regulate their proliferation and/or differentiation. Our findings suggest the involvement of FABP7 and FABP5 in the pathophysiology of demyelinating disorders,neuropsychiatric disorder and glioma,conditions in which OPCs/oligodendrocytes play central roles. View Publication

Hypoxia is a near-universal feature of cancer,promoting glycolysis,cellular proliferation,and angiogenesis. The molecular mechanisms of hypoxic signaling have been intensively studied,but the impact of changes in oxygen partial pressure (pO2) on the state of signaling networks is less clear. In a glioblastoma multiforme (GBM) cancer cell model,we examined the response of signaling networks to targeted pathway inhibition between 21% and 1% pO2. We used a microchip technology that facilitates quantification of a panel of functional proteins from statistical numbers of single cells. We find that near 1.5% pO2,the signaling network associated with mammalian target of rapamycin (mTOR) complex 1 (mTORC1)--a critical component of hypoxic signaling and a compelling cancer drug target--is deregulated in a manner such that it will be unresponsive to mTOR kinase inhibitors near 1.5% pO2,but will respond at higher or lower pO2 values. These predictions were validated through experiments on bulk GBM cell line cultures and on neurosphere cultures of a human-origin GBM xenograft tumor. We attempt to understand this behavior through the use of a quantitative version of Le Chatelier's principle,as well as through a steady-state kinetic model of protein interactions,both of which indicate that hypoxia can influence mTORC1 signaling as a switch. The Le Chatelier approach also indicates that this switch may be thought of as a type of phase transition. Our analysis indicates that certain biologically complex cell behaviors may be understood using fundamental,thermodynamics-motivated principles. View Publication

BACKGROUND AKI is a common sequela of infection with SARS-CoV-2 and contributes to the severity and mortality from COVID-19. Here,we tested the hypothesis that kidney alterations induced by COVID-19-associated AKI could be detected in cells collected from urine. METHODS We performed single-cell RNA sequencing (scRNAseq) on cells recovered from the urine of eight hospitalized patients with COVID-19 with (n=5) or without AKI (n=3) as well as four patients with non-COVID-19 AKI (n=4) to assess differences in cellular composition and gene expression during AKI. RESULTS Analysis of 30,076 cells revealed a diverse array of cell types,most of which were kidney,urothelial,and immune cells. Pathway analysis of tubular cells from patients with AKI showed enrichment of transcripts associated with damage-related pathways compared with those without AKI. ACE2 and TMPRSS2 expression was highest in urothelial cells among cell types recovered. Notably,in one patient,we detected SARS-CoV-2 viral RNA in urothelial cells. These same cells were enriched for transcripts associated with antiviral and anti-inflammatory pathways. CONCLUSIONS We successfully performed scRNAseq on urinary sediment from hospitalized patients with COVID-19 to noninvasively study cellular alterations associated with AKI and established a dataset that includes both injured and uninjured kidney cells. Additionally,we provide preliminary evidence of direct infection of urinary bladder cells by SARS-CoV-2. The urinary sediment contains a wealth of information and is a useful resource for studying the pathophysiology and cellular alterations that occur in kidney diseases. View Publication

Mutations causing loss of the NF-$\kappa$B regulator I$\kappa$BNS,result in impaired development of innate-like B cells and defective plasma cell (PC) differentiation. Since productive PC differentiation requires B cell metabolic reprogramming,we sought to investigate processes important for this transition using the bumble mouse strain,deficient for I$\kappa$BNS. We report that LPS-activated bumble B cells exhibited elevated mTOR activation levels,mitochondrial accumulation,increased OXPHOS and mROS production,along with a reduced capacity for autophagy,compared to wildtype B cells. Overall,our results demonstrate that PC differentiation in the absence of I$\kappa$BNS is characterized by excessive activation during early rounds of B cell division,increased mitochondrial metabolism and decreased autophagic capacity,thus improving our understanding of the role of I$\kappa$BNS in PC differentiation. View Publication

SummaryFocusing on the early stages of Alzheimer’s disease (AD) holds great promise. However,the specific events in neural cells preceding AD onset remain elusive. To address this,we utilized human-induced pluripotent stem cells carrying APPswe mutation to explore the initial changes associated with AD progression. We observed enhanced neural activity and early neuronal differentiation in APPswe cerebral organoids cultured for one month. This phenomenon was also evident when neural progenitor cells (NPCs) were differentiated into neurons. Furthermore,transcriptomic analyses of NPCs and neurons confirmed altered expression of neurogenesis-related genes in APPswe NPCs. We also found that the upregulation of reactive oxygen species (ROS) is crucial for early neuronal differentiation in these cells. In addition,APPswe neurons remained immature after initial differentiation with increased susceptibility to toxicity,providing valuable insights into the premature exit from the neural progenitor state and the increased vulnerability of neural cells in AD. Graphical abstract Highlights•APPswe organoids show increased neural activity and early differentiation•Enhanced ROS levels are necessary but insufficient to accelerate differentiation•Transcriptome analysis of APPswe NPCs shows gene expression shift to differentiation•Premature neural cells with APPswe exhibit increased vulnerability to toxicity Molecular biology; Neuroscience; Cell biology View Publication

The in vitro oxygen microenvironment profoundly affects the capacity of cell cultures to model physiological and pathophysiological states. Cell culture is often considered to be hyperoxic,but pericellular oxygen levels,which are affected by oxygen diffusivity and consumption,are rarely reported. Here,we provide evidence that several cell types in culture actually experience local hypoxia,with important implications for cell metabolism and function. We focused initially on adipocytes,as adipose tissue hypoxia is frequently observed in obesity and precedes diminished adipocyte function. Under standard conditions,cultured adipocytes are highly glycolytic and exhibit a transcriptional profile indicative of physiological hypoxia. Increasing pericellular oxygen diverted glucose flux toward mitochondria,lowered HIF1α activity,and resulted in widespread transcriptional rewiring. Functionally,adipocytes increased adipokine secretion and sensitivity to insulin and lipolytic stimuli,recapitulating a healthier adipocyte model. The functional benefits of increasing pericellular oxygen were also observed in macrophages,hPSC-derived hepatocytes and cardiac organoids. Our findings demonstrate that oxygen is limiting in many terminally-differentiated cell types,and that considering pericellular oxygen improves the quality,reproducibility and translatability of culture models. View Publication

The SARS-CoV-2 pandemic affecting the human respiratory system severely challenges public health and urgently demands for increasing our understanding of COVID-19 pathogenesis,especially host factors facilitating virus infection and replication. SARS-CoV-2 was reported to enter cells via binding to ACE2,followed by its priming by TMPRSS2. Here,we investigate ACE2 and TMPRSS2 expression levels and their distribution across cell types in lung tissue (twelve donors,39,778 cells) and in cells derived from subsegmental bronchial branches (four donors,17,521 cells) by single nuclei and single cell RNA sequencing,respectively. While TMPRSS2 is strongly expressed in both tissues,in the subsegmental bronchial branches ACE2 is predominantly expressed in a transient secretory cell type. Interestingly,these transiently differentiating cells show an enrichment for pathways related to RHO GTPase function and viral processes suggesting increased vulnerability for SARS-CoV-2 infection. Our data provide a rich resource for future investigations of COVID-19 infection and pathogenesis. View Publication

Ligand-activated glucocorticoid receptor (GR) elicits variable glucocorticoid-modulated transcriptomes in different cell types. However,some genes,including Kr{\{u}}ppel-like factor 9 (KLF9) a putative transcriptional repressor demonstrate conserved responses. We show that glucocorticoids induce KLF9 expression in the human airways in vivo and in differentiated human bronchial epithelial (HBE) cells grown at air-liquid interface (ALI). In A549 and BEAS-2B pulmonary epithelial cells glucocorticoids induce KLF9 expression with similar kinetics to primary HBE cells in submersion culture. A549 and BEAS-2B ChIP-seq data reveal four common glucocorticoid-induced GR binding sites (GBSs). Two GBSs mapped to the 5'-proximal region relative to KLF9 transcription start site (TSS) and two occurred at distal sites. These were all confirmed in primary HBE cells. Global run-on (GRO)-sequencing indicated robust enhancer RNA (eRNA) production from three of these GBSs in BEAS-2B cells. This was confirmed in A549 cells plus submersion and ALI culture of HBE cells. Cloning each GBS into luciferase reporters revealed glucocorticoid-induced activity requiring a glucocorticoid response element (GRE) within each distal GBS. While the proximal GBSs drove modest reporter induction by glucocorticoids this region exhibited basal eRNA production RNA polymerase II enrichment and looping to the TSS plausibly underlying constitutive KLF9 expression. Post-glucocorticoid treatment interactions between distal and proximal GBSs and the TSS correlated with KLF9 induction. CBP/P300 silencing reduced proximal GBS activity but negligibly effected KLF9 expression. Overall a model for glucocorticoid-mediated regulation of KLF9 involving multiple GBSs is depicted. This work unequivocally demonstrates that mechanistic insights gained from cell-lines can translate to physiologically relevant systems." View Publication

Cancer stem cells (CSC) are purported to initiate and maintain tumor growth. Deregulation of normal stem cell signaling may lead to the generation of CSCs; however,the molecular determinants of this process remain poorly understood. Here we show that the transcriptional coactivator YAP1 is a major determinant of CSC properties in nontransformed cells and in esophageal cancer cells by direct upregulation of SOX9. YAP1 regulates the transcription of SOX9 through a conserved TEAD binding site in the SOX9 promoter. Expression of exogenous YAP1 in vitro or inhibition of its upstream negative regulators in vivo results in elevated SOX9 expression accompanied by the acquisition of CSC properties. Conversely,shRNA-mediated knockdown of YAP1 or SOX9 in transformed cells attenuates CSC phenotypes in vitro and tumorigenicity in vivo. The small-molecule inhibitor of YAP1,verteporfin,significantly blocks CSC properties in cells with high YAP1 and a high proportion of ALDH1(+). Our findings identify YAP1-driven SOX9 expression as a critical event in the acquisition of CSC properties,suggesting that YAP1 inhibition may offer an effective means of therapeutically targeting the CSC population. View Publication