Throughout postnatal life in mammals, neural stem cells (NSCs) are located in the subventricular zone (SVZ) of the lateral ventricles. The greatest diversity of neuronal and glial lineages they generate occurs during early postnatal life in a region-specific manner. In order to evaluate potential heterogeneity in the NSC pool, we microdissected the dorsal and lateral SVZ at different postnatal ages and isolated NSCs and their immediate progeny based on their expression of Hes5-EGFP/Prominin1 and Ascl1-EGFP, respectively. Whole genome comparative transcriptome analysis revealed transcriptional regulators as major hallmarks that sustain postnatal SVZ regionalization. Manipulation of single genes encoding for locally enriched transcription factors influenced NSC specification indicating that the fate of regionalized postnatal SVZ NSCs can be readily modified . These findings reveal functional heterogeneity of NSCs in the postnatal SVZ and provide targets to recruit region-specific lineages in regenerative contexts.
Transcriptional Hallmarks of Heterogeneous Neural Stem Cell Niches of the Subventricular Zone.
Specimen part
View SamplesBalanced immune responses in airways of patients with asthma are crucial to succesful clearance of viral infection and proper asthma control.
Rhinovirus-induced epithelial RIG-I inflammasome suppresses antiviral immunity and promotes inflammation in asthma and COVID-19.
Subject, Time
View SamplesChronic infection with the bacterial pathogen Helicobacter pylori is a risk factor for the development of gastric cancer, yet remains asymptomatic in a majority of individuals. We report here that the C57Bl6 mouse model of experimental infection with the closely related H. felis recapitulates this wide range in host susceptibility. A majority of infected mice develop premalignant lesions such as gastric atrophy, compensatory epithelial hyperplasia and intestinal metaplasia, whereas a minority is completely protected from preneoplasia. Protection is associated with the failure to mount an IFN-gamma response to the infection and an associated high Helicobacter burden. We demonstrate that IFN-gamma is essential for clearance of Helicobacter, but also mediates the formation of preneoplastic lesions. We further provide evidence that IFN-gamma triggers a specific transcriptional program in murine gastric epithelial cells in vitro and in vivo, and induces their preferential transformation to the hyperplastic phenotype. In summary, our data suggest a dual role for IFN-gamma in Helicobacter pathogenesis that could provide an explanation for the differential susceptibility to H. pylori-induced gastric pathology in the human population.
No associated publication
Treatment
View SamplesGDAP1 is a mitochondrial fission factor and mutations in GDAP1 cause Charcot-Marie-Tooth disease. Gdap1 knockout mice, mimicking genetic alterations of patients suffering from severe CMT forms, develop an age-related, hypomyelinating peripheral neuropathy.
The Gdap1 knockout mouse mechanistically links redox control to Charcot-Marie-Tooth disease.
Specimen part
View SamplesChemokines and adhesion molecules upregulated in lymphatic endothelial cells (LECs) during tissue inflammation are believed to enhance dendritic cell (DC) migration to draining lymph nodes (dLNs), but the in vivo control of this process is not well understood. By performing transcriptional profiling of LECs isolated from murine skin, we found that inflammation induced by a contact hypersensitivity (CHS) response upregulated the adhesion molecules ICAM-1 and VCAM-1 and inflammatory chemokines in LECs. Furthermore, lymphatic lineage markers like Prox-1, VEGFR3 and LYVE-1 were significantly downregulated during CHS. By contrast, skin inflammation induced by Complete Freunds adjuvant (CFA) induced a different pattern of chemokine and lymphatic marker gene expression and almost no ICAM-1 up-regulation in LECs. In FITC painting experiments, DC migration to dLNs was more strongly increased in CFA- as compared to CHS-induced inflammation. Interestingly, DC migration did not correlate with the induction of CCL21 and ICAM-1 in LECs. However, the requirement for CCR7 signaling became further pronounced during inflammation, whereas CCR7-independent signals only had a minor role in enhancing DC migration. Collectively, these findings indicate that inflammation-induced DC migration is stimulus-dependent and only moderately enhanced by LEC-induced genes other than CCL21.
Tissue inflammation modulates gene expression of lymphatic endothelial cells and dendritic cell migration in a stimulus-dependent manner.
Sex, Age, Specimen part
View SamplesUnderstanding the nature of the various glucose-derived signals for insulin secretion (both triggering and amplifying) is essential for gaining insight into the functional failure of the beta-cells in diabetes and the development of drugs for correcting this problem. The beta-cells uniquely couple changes in cellular metabolism to electrical activity and thus insulin release. In mice, beta-cell specific deletion of the von Hippel-Lindau (VHL) tumor suppressor protein leads to the activation of a HIF transcription program that includes genes involved in glycolysis, suppression of mitochondrial activity and lactate production. This reprogramming of cellular metabolism results in abnormal insulin secretion properties.
No associated publication
Sex, Age
View SamplesThe aim of our study is to determine the functions of histone deacetylases (HDACs) 1 and 2 in Schwann cells during postnatal development of the peripheral nervous system (PNS). Schwann cells are the myelinating glial cells of the PNS. At birth, mouse sciatic nerves mature in 2 subsequent phases: 1/ big caliber axons get sorted into a 1 to 1 relationship with Schwann cells, 2/ Schwann cells build a myelin sheath around sorted axons. In mice where both HDAC1 & HDAC2 have been specifically knocked out in Schwann cells, both phases are impaired. HDACs are chromatin remodeling enzymes, they can thus alter gene expression directly. We want to identify which genes controlled by HDAC1 and HDAC2 in Schwann cells are necessary for the maturation of sciatic nerves. Because HDAC1 and HDAC2 can compensate for each other loss to some extend, we will first analyze changes of gene expression in HDAC1/HDAC2 double KO animals. We expect to gain critical insights into the molecular mechanisms controlling Schwann cell differentiation and myelination. This knowledge is of key importance for the success of regenerative medicine in peripheral neuropathies, nerve tumors, and transplantation paradigms in non-regenerative CNS lesions and in large PNS injuries.
HDAC1 and HDAC2 control the transcriptional program of myelination and the survival of Schwann cells.
Disease, Disease stage
View SamplesThe liver is frequently challenged by surgery-induced metabolic overload, viruses, or toxins, which induce the formation of reactive oxygen species. To determine the effect of oxidative stress on liver regeneration and to identify the underlying signalling pathways, we studied liver repair in mice lacking the Nrf2 transcription factor. In these animals, expression of several cytoprotective enzymes was reduced in hepatocytes, resulting in oxidative stress. As a consequence, tissue damage was aggravated, and liver regeneration after partial hepatectomy was delayed.
Impaired liver regeneration in Nrf2 knockout mice: role of ROS-mediated insulin/IGF-1 resistance.
Specimen part
View SamplesZebrafish (Danio rerio) were obtained from the Zebrafish Research Facility maintained in the Center for Environmental Biotechnology at the University of Tennessee. Fish husbandry, spawning, and experimental procedures were conducted with approval from the University of Tennessee Institutional Animal Care and Use Committee (Protocol #1690-1007). Water for holding fish and conducting experiments (hereafter referred to as fish water) consisted of MilliQ water (Millipore, Bedford, MA) with ions added: 19 mg/L NaHCO3, 1 mg/L sea salt (Instant Ocean Synthetic Sea Salt, Mentor, OH), 10 mg/L CaSO4, 10 mg/L MgSO4, 2 mg/L KCl. Embryos were obtained by spawning adult fish with no history of contaminant exposure. Fertilization of embryos took place at the same time ( 15 min.), such that larvae used in experiments were of similar age at the time of exposure. All activities (maintenance of adult fish, spawning, and experiments) were conducted in an environmental chamber with a temperature of 27 1 C and 14:10h light:dark photoperiod.
Global gene expression profiling in larval zebrafish exposed to microcystin-LR and microcystis reveals endocrine disrupting effects of Cyanobacteria.
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View SamplesTarget genes of Fbxl10 during 3T3-L1 adipogenesis was analyzed
The FBXL10/KDM2B scaffolding protein associates with novel polycomb repressive complex-1 to regulate adipogenesis.
Cell line, Treatment
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