BACKGROUND:Dynamic transcriptional regulation is critical for an organism's response to environmental signals and yet remains elusive to capture. Such transcriptional regulation is mediated by master transcription factors (TF) that control large gene regulatory networks. Recently, we described a dynamic mode of TF regulation named "hit-and-run". This model proposes that master TF can interact transiently with a set of targets, but the transcription of these transient targets continues after the TF dissociation from the target promoter. However, experimental evidence validating active transcription of the transient TF-targets is still lacking.
"Hit-and-Run" transcription: de novo transcription initiated by a transient bZIP1 "hit" persists after the "run".
Specimen part
View SamplesTo realize cell transplantation therapy for Parkinson's disease (PD), the grafted neurons should be integrated into the host neuronal circuit in order to restore the lost neuronal function. Here, using wheat germ agglutinin-based trans-synaptic tracing, we show that integrin 5 is selectively expressed in striatal neurons that are innervated by midbrain dopaminergic (DA) neurons from the mouse experiments. Additionally, we found that integrin 51 was activated by the administration of estradiol-2-benzoate (E2B) in striatal neurons of adult female rats. Importantly, we observed that the systemic administration of E2B into hemi-parkinsonian rat models facilitates the functional integration of grafted DA neurons derived from human induced pluripotent stem cells into the host striatal neuronal circuit via the activation of integrin 51. Finally, methamphetamine-induced abnormal rotation was recovered earlier in E2B-administrated rats than in rats that received other regimens. Our results suggest that the simultaneous administration of E2B with stem cell-derived DA progenitors can enhance the efficacy of cell transplantation therapy for PD.
Estradiol Facilitates Functional Integration of iPSC-Derived Dopaminergic Neurons into Striatal Neuronal Circuits via Activation of Integrin α5β1.
Specimen part
View SamplesWe performed global scale microarray analysis to identify detailed mechanisms by which nonpermissive temperature induces cell growth arrest and differentiation in tracheal epithelial RTEC11 cells harboring temperature-sensitive simian virus 40 large T-antigen by using an Affymetrix GeneChip system. Tracheal epithelial RTEC11 cells used in this study were derived from transgenic rats harboring a temperature-sensitive simian virus 40 large T-antigen. Although the cells grew continuously at the permissive temperature, the nonpermissive temperature led to cell growth arrest and differentiation.
Establishment and functional characterization of a tracheal epithelial cell line RTEC11 from transgenic rats harboring temperature-sensitive simian virus 40 large T-antigen.
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View SamplesAlthough various mechanisms have been inferred for combinatorial actions of multiple carcinogens, these mechanisms have not been well demonstrated in experimental carcinogenesis models. We evaluated mammary carcinogenesis initiated by combined exposure to various doses of radiation and chemical carcinogens. Female rats at 7 weeks of age were -irradiated (0.22 Gy) and/or exposed to 1-methyl-1-nitrosourea (20 or 40 mg/kg, single intraperitoneal injection) or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (40 mg/kg/day by gavage for 10 days) and were observed until 50 weeks of age. The incidence of mammary carcinoma increased steadily as a function of radiation dose in the absence of chemicals; mathematical analysis supported an additive increase when radiation was combined with a chemical carcinogen, irrespective of the chemical species and its dose. Hras mutations were characteristic of carcinomas that developed after chemical carcinogen treatments and were overrepresented in carcinomas induced by the combination of radiation and MNU (but not PhIP), indicating an interaction of radiation and MNU at the level of initiation. The expression profiles of seven classifier genes, previously shown to distinguish two classes of rat mammary carcinomas, categorized almost all examined carcinomas that developed after individual or combined treatments with radiation (1 Gy) and chemicals as belonging to a single class; more comprehensive screening using microarrays and a separate test sample set failed to identify differences in gene expression profiles among these carcinomas. These results suggest that a complex, multilevel interaction underlies the combinatorial action of radiation and chemical carcinogens in the experimental model.
Molecular characterization of cancer reveals interactions between ionizing radiation and chemicals on rat mammary carcinogenesis.
Specimen part
View SamplesHuman induced pluripotent stem cells (iPSCs) can provide a promising source of midbrain dopaminergic (mDA) neurons for cell replacement therapy for Parkinson's disease (PD). However, iPSC-derived donor cells inevitably contain tumorigenic or inappropriate cells. To eliminate these unwanted cells, cell sorting using antibodies for specific markers such as CORIN or ALCAM have been developed, but neither marker is specific for ventral midbrain. Here, we employed a double-selection strategy for cells expressing both CORIN and LMX1A::GFP and report a novel cell surface marker to enrich mDA progenitors, LRTM1. When transplanted into 6-OHDA-lesioned rats, human iPSC-derived LRTM1+ cells survived and differentiated into mDA neurons in vivo, resulting in significant improvement in motor behavior without tumor formation. In addition, LRTM1+ cells exhibited efficient survival of mDA neurons in the brain of an MPTP-treated monkey. Thus, LRTM1 can provide a powerful tool for efficient and safe cell therapy for PD patients.
Purification of functional human ES and iPSC-derived midbrain dopaminergic progenitors using LRTM1.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Endometrial-peritoneal interactions during endometriotic lesion establishment.
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View SamplesHuman induced pluripotent stem cells (iPSCs) can provide a promising source of midbrain dopaminergic (DA) neurons for cell replacement therapy for Parkinsons disease. However, iPSC-derived donor cells may inevitably contain tumorigenic or inappropriate cells. Purification of neural progenitor cells or DA neurons as suitable donor cells has been attempted, but the isolation of DA progenitor cells derived from human pluripotent stem cells has so far been unsuccessful. Here we show human iPSC-derived DA progenitor cells can be efficiently isolated by cell sorting using a floor plate marker, Corin. we were able to develop a method for 1) scalable DA neuron induction on human laminin fragment and 2) sorting DA progenitor cells using an anti-Corin antibody. Furthermore, we determined the optimal timing for the cell sorting and transplantation. The grafted cells survived well and functioned as midbrain DA neurons in the 6-OHDA-lesioned rats, and showed minimal risk of tumor formation. The sorting of Corin-positive cells is favorable in terms of both safety and efficiency, and our protocol will contribute to the clinical application of human iPSCs for Parkinsons disease.
Isolation of human induced pluripotent stem cell-derived dopaminergic progenitors by cell sorting for successful transplantation.
Specimen part
View SamplesThe pathophysiology of endometriotic lesion development remains unclear but involves a complex interaction between ectopic endometrium and host peritoneal tissues. We hypothesised that disruption of this interaction was likely to suppress endometriotic lesion formation. We hoped to delineate the molecular and cellular dialogue between ectopic human endometrium and peritoneal tissues in nude mice, as a first step towards testing this hypothesis. Human endometrium was xenografted into nude mice and the resulting lesions were analysed using microarrays. A novel technique was developed that unambiguously determined whether RNA transcripts identified by the microarray analyses originated from human cells (endometrium) or mouse cells (stroma). Four key pathways (ubiquitin/proteosome, inflammation, tissue remodelling/repair and ras-mediated oncogenesis) were revealed, that demonstrated communication between host stromal cells and ectopic endometrium.
Endometrial-peritoneal interactions during endometriotic lesion establishment.
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View SamplesThe pathophysiology of endometriotic lesion development remains unclear but involves a complex interaction between ectopic endometrium and host peritoneal tissues. We hypothesised that disruption of this interaction was likely to suppress endometriotic lesion formation. We hoped to delineate the molecular and cellular dialogue between ectopic human endometrium and peritoneal tissues in nude mice, as a first step towards testing this hypothesis. Human endometrium was xenografted into nude mice and the resulting lesions were analysed using microarrays. A novel technique was developed that unambiguously determined whether RNA transcripts identified by the microarray analyses originated from human cells (endometrium) or mouse cells (stroma). Four key pathways (ubiquitin/proteosome, inflammation, tissue remodelling/repair and ras-mediated oncogenesis) were revealed, that demonstrated communication between host stromal cells and ectopic endometrium.
Endometrial-peritoneal interactions during endometriotic lesion establishment.
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View SamplesKRAP (Ki-ras-induced actin-interacting protein) is a cytoskeleton-associated protein and a ubiquitous protein among tissues, originally identified as a cancer-related molecule. KRAP-deficient (KRAP-/-) mice show enhanced metabolic rate, decreased adiposity, improved glucose tolerance, hypoinsulinemia and hypoleptinemia. KRAP-/- mice are also protected against high-fat diet-induced obesity and insulin resistance despite of hyperphagia.
Altered energy homeostasis and resistance to diet-induced obesity in KRAP-deficient mice.
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