It remains controversial whether the routes from differentiated cells to iPSCs are related to the reverse order of normal developmental processes or independent of them. Here, we generated iPSCs from mouse astrocytes by three (Oct3/4, Klf4 and Sox2 (OKS)), two (OK), or four (OKS plus c-Myc) factors. Sox1, a neural stem cell (NSC)-specific transcription factor, is transiently upregulated during reprogramming and Sox1-positive cells become iPSCs. The upregulation of Sox1 is essential for OK-induced reprogramming. Genome-wide analysis revealed that the gene expression profile of Sox1-expressing intermediate-state cells resembles that of NSCs. Furthermore, the intermediate-state cells are able to generate neurospheres, which can differentiate into both neurons and glial cells. Remarkably, during MEF reprogramming, neither Sox1 upregulation nor an increase in neurogenic potential occurs. Thus, astrocytes are reprogrammed through an NSC-like state, suggesting that reprogramming partially follows the retrograde pathway of normal developmental processes.
Induction of Pluripotency in Astrocytes through a Neural Stem Cell-like State.
Specimen part
View SamplesThe combination of Wnt pathway activation by the GSK3 inhibitor and ERK pathway inhibition by the MEK inhibitor, which is known as 2i is a well-established method to maintain mouse embryonic stem cell (mESC) self-renewal. Here we show that Activin A also has the ability to promote naive pluripotency of mESCs when combined with the MEK inhibitor PD0325901. mESCs were efficiently propagated in a medium containing both Activin A and the MEK inhibitor (PD0325901). mESCs cultured in Activin+PD retained a pluripotency state that expresses high levels of naive pluripotency-related transcription factors and is able to differentiate into three germ layers under appropriate conditions. They also showed naive pluripotency features, including the preferential usage of the Oct4 distal enhancer and the self-renewal response to Wnt pathway activation. Our finding provides another way to maintain the naive pluripotency state and reveals a role of Activin/Nodal/TGF- signaling in stabilizing self-renewal gene regulatory networks in mESCs.
Activin A in combination with ERK1/2 MAPK pathway inhibition sustains propagation of mouse embryonic stem cells.
Specimen part, Treatment
View SamplesOur previous study using nude rats revealed that the parental JDCaP xenografts predominantly expressed full-length androgen receptor (AR) whereas the relapsed JDCaP xenografts after castration acquired AR splice variants including AR-V7 and ARv567es. To understand molecular mechanisms underlying the acquisition of AR splice variants in the JDCaP model, we performed microarray analysis using RNA samples of the xenografts without castration (Parent), the relapsed xenografts overexpressing full-length AR and AR-V7 (ARhiV7hi), and the relapsed xenografts expressing ARv567es (ARv567es).
The RNA helicase DDX39B and its paralog DDX39A regulate androgen receptor splice variant AR-V7 generation.
Specimen part
View SamplesGlobal DNA hypomethylation and DNA hypermethylation of promoter regionsincluding tumor suppressor genesare frequently detected in human cancers. Although many studies have suggested a contribution to carcinogenesis, it is still unclear whether the aberrant DNA hypomethylation observed in tumors is a consequence or a cause of cancer. We found that overexpression of Stella (also known as PGC7, Dppa3), a maternal factor required for the maintenance of DNA methylation in early embryos, induced global DNA hypomethylation and transformation in NIH3T3 cells. This hypomethylation was due to the binding of Stella to Np95 (also known as Uhrf1, ICBP90) and the subsequent impairment of Dnmt1 localization. In addition, enforced expression of Stella enhanced the metastatic ability of B16 melanoma cells through the induction of metastasis-related genes by inducing DNA hypomethylation of their promoter regions. Such DNA hypomethylation itself causes cellular transformation and metastatic ability. These data provide new insight into the function of global DNA hypomethylation in carcinogenesis.
Global DNA hypomethylation coupled to cellular transformation and metastatic ability.
Cell line
View SamplesBrassinosteroid (BR) and auxin co-regulate plant growth in a process termed cross-talking. Based on the assumption that their signal transductions are partially shared, inhibitory chemicals for both signal transductions were screened from a commercially-available library. A chemical designated as NJ15 (ethyl 2-[5-(3,5-dichlorophenyl)-1,2,3,4-tetrazole-2-yl]acetate) diminished the growth promotion of both adzuki bean epicotyls and Arabidopsis seedlings, by either the application of BR or auxin. To understand its target site(s), bioassays with a high dependence on either the signal transduction of BR (BR-signaling) or of auxin (AX-signaling), were performed. NJ15 inhibited photomorphogenesis of Arabidopsis seedlings grown in the dark, which mainly depends on BR-signaling, while NJ15 also inhibited their gravitropic responses mainly depending on AX-signaling. On the study for the structure-activity relationships of NJ15 analogues, they showed strong correlations on the inhibitory profiles between BR- and AX-signalings. These correlations imply that NJ15 targets the downstream pathway after the integration of BR- and AX-signals.
Does the brassinosteroid signal pathway in photomorphogenesis overlap with the gravitropic response caused by auxin?
Age, Specimen part, Treatment
View SamplesGABAergic interneuron in the cortex comprise a very heterogenous group. and it is critical to identify discrete interneuron types to understand how their contributions to behavior can be modulated by external and internal cues. However, molecular difinition of these interneuron cell groups has been difficult. Comparative analysis of different interneuron subtypes can provide us new candidate marker genes which could target more specific interneuon cell group. Here we identify oxytocin responsive novel class of interneuron through our comparative analysis.
Oxytocin modulates female sociosexual behavior through a specific class of prefrontal cortical interneurons.
Specimen part
View SamplesHuman embryonic stem cells (hESCs) are a powerful tool for modeling regenerative therapy. To search for the genes that promote hematopoietic development from human pluripotent stem cell, we overexpressed a list of hematopoietic regulator genes in human pluripotent stem cell-derived CD34+CD43- endothelial cells (ECs) enriched in hemogenic endothelium. Among genes tested, only SOX17, a gene encoding a transcription factor of the SOX family, promoted cell growth and supported expansion of CD34+CD43+CD45-/low cells expressing a hemogenic endothelial maker VE-cadherin. SOX17 was highly expressed in CD34+CD43- ECs but at a low level in CD34+CD43+CD45- pre-hematopoietic progenitor cells (pre-HPCs) and CD34+CD43+CD45+ HPCs. SOX17-overexpressing cells formed sphere-like colonies and generated few hematopoietic progenies. However, they retained hemogenic potential and gave rise to hematopoietic progenies upon inactivation of SOX17. Global gene expression analyses revealed that the CD34+CD43+CD45-/low cells expanded upon overexpression of SOX17 are hemogenic endothelium-like cells developmentally placed between ECs and pre-HPCs. Of interest, SOX17 also reprogrammed both pre-HPCs and HPCs into hemogenic endothelium-like cells. Genome-wide mapping of SOX17 revealed that SOX17 directly activates transcription of key regulator genes for vasculogenesis, hematopoiesis, and erythrocyte differentiation. Depletion of SOX17 in CD34+CD43- ECs severely compromised their hemogenic activity. These findings suggest that SOX17 plays a critical role in priming hemogenic potential in ECs, thereby regulates hematopoietic development from hESCs.
Role of SOX17 in hematopoietic development from human embryonic stem cells.
Specimen part, Disease
View SamplesOverexpression of transcription factor Sox17 in human ES cells-derived endothelial cells and hematopoietic cells enhances expansion of hemogenic endothelium-like cells.
Role of SOX17 in hematopoietic development from human embryonic stem cells.
Specimen part
View SamplesThe gut microbiota is essential for several aspects of host physiology such as metabolism, epithelial barrier function and immunity. Previous studies have revealed that host immune system as well as diet and other environmental factors have a strong impact on the composition and activity of gut microbiota, but the molecular requirements for such functional regulation remain unknown. We show that the bacteria belonging to phylum Bacteroidetes acquire their symbiotic activity in the colonic mucus, depending on a newly characterized molecular family encoded within the polysaccharide utilization loci (PUL), which we have named Mucus-Associated Functional Factor (MAFF).
IgA regulates the composition and metabolic function of gut microbiota by promoting symbiosis between bacteria.
Sex, Specimen part
View SamplesThe Arabidopsis RWP-RK protein RKD4 is expressed specifically in early embryogenesis and triggers embryonic cell division sequences. We used Affymetrix ATH1 microarrays to analyze the pattern of gene expression changes in response to induced ectopic expression of RKD4 in post-embryonic organs.
The Arabidopsis RWP-RK protein RKD4 triggers gene expression and pattern formation in early embryogenesis.
Specimen part, Disease
View Samples