Across life neural stem cells (NSCs) generate new neurons in the mammalian brain through asymmetric neurogenic and self-renewing cell divisions. However, the cellular mechanisms underlying NSC asymmetry remain unknown. Using fluorescence loss in photobleaching (FLIP) we here show that NSCs in vitro and within the developing forebrain generate a lateral diffusion barrier during cell division resulting in asymmetric segregation of cellular components. The strength of the diffusion barrier is dynamically regulated with age and depends on the proper function of lamin-associated nuclear envelope constituents. Strikingly, age-associated or experimental impairment of the diffusion barrier disrupts asymmetric segregation of damaged proteins, a product of aging. Thus, the data presented here identify a mechanism how age is asymmetrically distributed during somatic stem cell division.
A mechanism for the segregation of age in mammalian neural stem cells.
Age, Specimen part
View SamplesVery little is known about splicing and its regulation in germ cells, particularly during meiosis. This paper describes the role of a male germ cell-specific protein, Tudor containing protein 6 (TDRD6), in assembly of the spliceosome in spermatocytes. We show that in spermatocytes, TDRD6 interacts with the key protein methyl transferase of the splicing pathway PRMT5. PRMT5 methylates arginines in substrate proteins. In a methylation dependent manner, TDRD6 also associates with spliceosomal core protein SmB in the absence of RNA, thus before an RNP-type spliceosome has been assembled. In Tdrd6-/- primary spermatocytes, PRMT5''s association with SmB and the arginine dimethylation of SmB are much reduced. Abrogation of arginine methylation impaired the assembly of spliceosomes and the presence of the spliceosomal RNA U5 is aberrantly increased. These deficiencies in spliceosome maturation correlated with decreased numbers of Cajal bodies and gems involved in later stages, i.e. nuclear snRNP maturation. To reveal functional consequences of these deficiencies, transcriptome analysis of primary spermatocytes showed high numbers of splicing defects such as aberrant usage of intron and exons as well as aberrant representation of splice junctions upon TDRD6 loss. This study reveals a novel function of TDRD6 in spliceosome maturation and mRNA splicing in spermatocytes. Overall design: Examination of splicing defects in isolated diplotene cells of 20dpp Tdrd6-/- vs. Tdrd6+/- testes pooled from at least 4 mice by deep sequencing in duplicate using Illumina® HiSeq 2500.
TDRD6 mediates early steps of spliceosome maturation in primary spermatocytes.
Specimen part, Subject
View SamplesWe used microarrays to detail the transcriptome-wide gene expression changes underlying chemical conversion of human fibroblasts into induced Schwann Cells over a time period of 39 days. We compared then the expression profiles of these induced Schwann Cells to primary Schwann cells.
Chemical conversion of human fibroblasts into functional Schwann cells.
Specimen part
View SamplesMechanisms controlling the proliferative activity of neural stem/progenitor cells (NSPCs) play a pivotal role to ensure life-long neurogenesis in the mammalian brain. How metabolic programs are coupled with NSPC activity remains unknown. Here we show that fatty acid synthase (FASN), the key enzyme of de novo lipogenesis, is highly active in adult NSPCs and that conditional deletion of FASN in NSPCs impairs adult neurogenesis. The rate of de novo lipid synthesis and subsequent proliferation of NSPCs is regulated by Spot14, a gene we found to be selectively expressed in low proliferating adult NSPCs. Spot14 reduces the availability of malonyl-CoA, which is an essential substrate for FASN to fuel lipogenesis. Thus, we here identified a functional coupling between the regulation of lipid metabolism and adult NSPC proliferation.
Metabolic control of adult neural stem cell activity by Fasn-dependent lipogenesis.
Specimen part
View SamplesThe polyphenol resveratrol has anti-inflammatory effects in various cells, tissues, animals and human settings of low-grade inflammation. Psoriasis is a disease of both localized and systemic low-grade inflammation. The Sirtuin1 enzyme thought to mediate the effects of resveratrol is present in skin and resveratrol is known to downregulate NF-B; a major contributor in the development of psoriasis. Consequently we investigated whether resveratrol has an effect on an Imiquimod induced psoriasis-like skin inflammation in mice and sought to identify candidate genes, pathways and interleukins mediating the observed effects. The study consisted of three treatment groups: A control group, an Imiquimod group and an Imiquimod+resveratrol group. Psoriasis severity was assessed using elements of the Psoriasis Area Severity Index, actual skin thickness measurements, and histological examination. We performed an RNA microarray from lesional skin and afterwards Ingenuity pathway analysis to identify affected signalling pathways. Our microarray was compared to a previously deposited microarray to determine if gene changes were psoriasis-like, and to a human microarray to determine if findings could be relevant in a human setting. Imiquimod treatment induced a psoriasis-like skin inflammation. Resveratrol significantly diminished the severity of the psoriasis-like skin inflammation. The RNA microarray revealed a psoriasis-like gene expression-profile in the Imiquimod treated group, and highlighted several resveratrol dependent changes in relevant genes, such as increased expression of genes associated with retinoic acid stimulation and reduced expression of genes involved in IL-17 dependent pathways (e.g.IL-17A, IL-17F,IL-23p19 ). Quantitative PCR confirmed a resveratrol dependent decrease in mRNA levels of IL-17A and IL-19; both central in developing psoriasis. In conclusion, resveratrol ameliorates psoriasis, and changes in expression of retinoic acid stimulated genes, IL-17 signalling pathways, IL-17A and IL-19 mRNA levels in a beneficial manner suggests it might have a role in the treatment of psoriasis and should be explored further in a human setting.
Resveratrol ameliorates imiquimod-induced psoriasis-like skin inflammation in mice.
Specimen part
View SamplesThe purpose of this study is to characterize gene expression changes that occur when conditional knock-out of Srf rescues mutant phenotypes in the cornea of Dstncorn1 mice.
Serum response factor: positive and negative regulation of an epithelial gene expression network in the destrin mutant cornea.
Specimen part
View SamplesCase story. A patient with massive infiltration of the visceral adipose tissue depot by BAT in a patient with a catecholamine secreting paraganglioma. BAT tissue was identified by protein expression of UCP1 (western blotting and immunostaining)
Chronic adrenergic stimulation induces brown adipose tissue differentiation in visceral adipose tissue.
Specimen part
View SamplesProprioception relies on two main classes of proprioceptive sensory neurons (pSNs). These neurons innervate two distinct peripheral receptors in muscle, muscle spindles (MSs) or Golgi tendon organs (GTOs), and synapse onto different sets of spinal targets, but the molecular basis of their distinct pSN subtype identity remains unknown.
The PDZ-domain protein Whirlin facilitates mechanosensory signaling in mammalian proprioceptors.
Sex, Specimen part
View SamplesProstate cancer is dependent on androgen receptor (AR) signaling at all stages of the disease and cyclin D1 has been shown to negatively modulate the expression of the AR-dependent gene prostate specific antigen (KLK3/PSA).
Cyclin D1 is a selective modifier of androgen-dependent signaling and androgen receptor function.
Cell line, Treatment
View SamplesPlexiform neurofibroma is a major contributor to morbidity in Neurofibromatosis type I (NF1) patients. Macrophages and mast cells infiltrate neurofibroma, and data from mouse models implicate these leukocytes in neurofibroma development. Anti-inflammatory therapy targeting these cell populations has been suggested as a means to prevent neurofibroma development. Here, we compare gene expression in inflamed nerves from NF1 models which invariably form neurofibroma to those with inflammation driven by EGFR overexpression which rarely progresses to neurofibroma. We find that the chemokine Cxcl10 is uniquely up-regulated in NF1 mice that invariably develop neurofibroma. Global deletion of the CXCL10 receptor, Cxcr3, prevented neurofibroma development in these neurofibroma-prone mice. Cxcr3 expression localized to T cells and dendritic cells (DCs) in both inflamed nerves and neurofibromas. These data support a heretofore unappreciated role for T cells/DCs in neurofibroma initiation. Overall design: To identify cell populations associated with Cxcl10 expression, we utilized a single-cell RNA-Seq (scRNA-Seq) data set collected from 2-month Dhh-Cre;Nf1 fl/fl nerve/DRG using the 10x Genomics Chromium platform.
Cxcr3-expressing leukocytes are necessary for neurofibroma formation in mice.
Age, Specimen part, Cell line, Subject
View Samples