The subunits of voltage-gated calcium channels regulate surface expression and gating of CaV1 and CaV2 1 subunits, and thus contribute to neuronal excitability, neurotransmitter release and calcium-induced gene regulation. In addition certain subunits are targeted into the nucleus, where they directly interact with the epigenetic machinery. Whereas their involvement in this multitude of functions is reflected by a great molecular heterogeneity of isoforms derived from four genes and abundant alternative splicing, little is known about the roles of individual variants in specific neuronal functions. In the present study, an alternatively spliced 4 subunit lacking the variable N-terminus (4e) is identified. It is highly expressed in mouse cerebellum and cultured cerebellar granule cells (CGC) and modulates P/Q-type calcium currents in tsA cells and CaV2.1 surface expression in neurons. Compared to the other two known full-length 4 variants (4a, 4b) 4e is most abundantly expressed in the distal axon, but lacks nuclear targeting properties. To examine the importance of nuclear targeting of 4 subunits for transcriptional regulation, we performed whole genome expression profiling of CGCs from lethargic mice individually reconstituted with 4a, 4b, and 4e. Notably, the number of genes regulated by each 4 splice variant correlated with the rank order of their nuclear targeting properties (4b> 4a> 4e). Together these findings support isoform-specific functions of 4 splice variant in neurons, with 4b playing a dual role in channel modulation and gene regulation, while the newly detected 4e variant serves exclusively in calcium channel-dependent functions.
Differential neuronal targeting of a new and two known calcium channel β4 subunit splice variants correlates with their regulation of gene expression.
Specimen part
View SamplesMouse back skin was disassociated to single cells, sorted by cell surface markers and tested by microarrray
Bald scalp in men with androgenetic alopecia retains hair follicle stem cells but lacks CD200-rich and CD34-positive hair follicle progenitor cells.
Sex, Age, Specimen part
View SamplesExercise training improves whole body glucose homeostasis through effects largely attributed to adaptations in skeletal muscle; however, training also affects other tissues including adipose tissue. To determine if exercise-induced adaptations to adipose tissue contribute to training-induced improvements in glucose homeostasis, subcutaneous white adipose tissue (scWAT) from trained or sedentary donor mice was transplanted into the visceral cavity of sedentary recipients. Remarkably, nine days post-transplantation, mice receiving trained scWAT had improved glucose tolerance and enhanced insulin sensitivity compared to mice transplanted with sedentary scWAT or sham-treated mice. Mice transplanted with trained scWAT had increased insulin-stimulated glucose uptake in tibialis anterior and soleus muscles and brown adipose tissue, suggesting that the transplanted scWAT exerted endocrine effects. Furthermore, the deleterious effects of high-fat feeding on glucose tolerance and insulin sensitivity were completely reversed if high-fat fed recipient mice were transplanted with trained scWAT. In additional experiments, voluntary exercise training by wheel running for only 11 days resulted in profound changes in scWAT including increased expression of 1550 genes involved in numerous cellular functions, including metabolism. Exercise training causes adaptations to scWAT that elicit metabolic improvements in other tissues, demonstrating a previously unrecognized role for adipose tissue in the beneficial effects of exercise on systemic glucose homeostasis.
A novel role for subcutaneous adipose tissue in exercise-induced improvements in glucose homeostasis.
Sex, Age, Specimen part
View SamplesThe generation of specific types of neurons from stem cells offers important opportunities in regenerative medicine. However, future applications and proper verification of cell identities will require stringent ways to generate homogenous neuronal cultures. Here we show that under permissive culturing conditions individual transcription factors can induce a desired neuronal lineage from virtually all expressing cells by a mechanism resembling developmental binary cell fate switching. Such efficient selection of cell fate resulted in remarkable cellular enrichment that enabled global gene expression validation of generated neurons and identification of novel features in the studied cell lineages. Several sources of stem cells have a limited competence to differentiate into e.g. dopamine neurons. However, we show that the combination of factors that normally promote either regional or dedicated neuronal specification can overcome limitations in cellular competence and promote efficient reprogramming also in more remote neural contexts, including human neural progenitor cells.
Transcription factor-induced lineage selection of stem-cell-derived neural progenitor cells.
Specimen part, Cell line
View SamplesHere we characterize and optimize both systems to increase their utility for preclinical studies. We show that TH-MYCN mice develop tumors in the paraspinal ganglia, but not in the adrenal, with cellular and gene expression patterns similar to human NB. In addition, we present a new ultrasound guided, non-invasive orthotopic xenograft method. This injection technique is rapid, provides accurate targeting of the injected cells and leads to efficient engraftment. We also demonstrate that tumors can be detected, monitored and quantified prior to visualization using ultrasound, MRI and bioluminescence. Finally we develop and test a standard of care chemotherapy regimen. This protocol, which is based on current treatments for neuroblastoma, provides a baseline for comparison of new therapeutic agents.
Preclinical models for neuroblastoma: establishing a baseline for treatment.
Specimen part
View SamplesPolarization of macrophages to M1 or M2 cells is important for mounting responses against bacterial and helminth infection respectively. Jumonji domain containing 3 (JMJD3), a histone 3 K27 demethylase, has been implicated in the activation of macrophages. Here we show that JMJD3 is essential for M2 macrophage polarization to helminth infection and chitin, though JMJD3 is dispensable for M1 responses. Furthermore, Jmjd3 is critical for proper bone marrow macrophage differentiation in a demethylase activity-dependent manner. Jmjd3 deficiency affected trimethylation of H3K27 in only a limited numbers of genes. Among them, we identified Irf4 as the target transcription factor critical for controlling M2 macrophage polarization. Collectively, these results show that JMJD3-mediated H3K27 demethylation is critical for regulating M2 macrophage development leading to anti-helminth host responses.
The Jmjd3-Irf4 axis regulates M2 macrophage polarization and host responses against helminth infection.
Specimen part, Treatment
View SamplesThe vertebrate retina uses diverse neuronal cell types arrayed into complex neural circuits to extract, process and relay information from the visual scene to the higher order processing centers of the brain. Amacrine cells, a diverse class of inhibitory interneurons, are thought to mediate the majority of the processing of the visual signal that occurs within the retina. Despite morphological characterization, the number of known molecular markers of amacrine cell types is still much smaller than the 26 morphological types that have been identified. Furthermore, it is not known how this diversity arises during development. Here, we have combined in vivo genetic labeling and single cell genome-wide expression profiling to: 1) Identify specific molecular types of amacrine cells; 2) Demonstrate the molecular diversity of the amacrine cell class.
Development and diversification of retinal amacrine interneurons at single cell resolution.
No sample metadata fields
View SamplesThe goal of the project was to isolate single miRNA-expressing cells labelled by GFP reporter genes under the control of endogenous miRNA promoters and analyze expression levels of miRNA target genes in these cells. GFP-positive miRNA-expressing cells and GFP-negative cells from the rest of the embryos were purified at the same developmental stage to the cellular resolution using fluorescent activated cell sorting (FACS). Focus was on regulation by miR-206 and miR-133 in the developing somites and miR-124 in the developing central nervous system. Comparison of wild-type embryos and those lacking miRNAs revealed predicted
Coherent but overlapping expression of microRNAs and their targets during vertebrate development.
No sample metadata fields
View SamplesScaffold proteins regulate intracellular MAP kinase signaling by providing critical spatial and temporal specificity. We have shown previously that the scaffold protein MEK1 partner (MP1) is localized to late endosomes by the adaptor protein p14. Using conditional gene disruption of p14 in livers of mice we analysed protein and transcript signatures in tissue samples. Further biological network analysis predicted that the differentially expressed transcripts and proteins are involved in cell cycle progression and regulation of cellular proliferation. Although some of the here identified signatures were previously linked to phospho-ERK activity, most of them were novel targets of late endosomal p14/MP1/MEK/ERK signaling module. Finally, the proliferation defect was confirmed in a chemically induced liver regeneration model in p14 liver knock-out mice.
Comprehensive proteomic and transcriptomic characterization of hepatic expression signatures affected in p14 liver conditional knockout mice.
Specimen part
View SamplesContinuous regeneration of digestive enzyme (zymogen) secreting chief cells is a normal aspect of stomach function that is disrupted in pre-cancerous lesions. Regulation of zymogenic cell (ZC) differentiation is poorly understood. Here we profile Parietal, Pit, and Zymogenic cells for comparison and study.
The maturation of mucus-secreting gastric epithelial progenitors into digestive-enzyme secreting zymogenic cells requires Mist1.
Specimen part
View Samples