The discovery of the small regulatory RNA populations has changed our vision of cellular regulations. Indeed, loaded on Argonaute proteins they formed ribonucleoprotein complexes that target complementary sequences and achieved widespread silencing mechanisms conserved in most eukaryotes. The recent development of deep sequencing approaches highly contributed to their detection. Small RNA isolation form cells and/or tissues remains a crucial stage to generate robust and relevant sequencing data. In 2006, a novel strategy based on anion-exchange chromatography has been purposed as an alternative to the standard size-isolation purification procedure. However, the eventual biases of such a method have been poorly investigated. Moreover, this strategy not only relies on advanced technical skills and expensive material but is time consuming and requires an elevated starting biological material amount. Using bioinformatic comparative analysis of six independent small RNA-sequencing libraries of Drosophila ovaries, we here demonstrate that anion-exchange chromatography purification prior to small RNA extraction unbiasedly enriches datasets in bona fide reads (small regulatory RNA reads) and depletes endogenous contaminants (ribosomal RNAs and degradation products). The resulting increase of sequencing depth provides a major benefit to study rare populations. We then developed a fast and basic manual procedure to purify loaded small non coding RNAs using anion-exchange chromatography at the bench. We validated the efficiency of this new method and used this strategy to purify small RNAs from various tissues and organisms. We moreover determined that our manual purification increases the output of the previously described anion-exchange chromatography procedure. Overall design: Comparison of small regulatory RNA populations obtained after three different small RNA purification procedures
A user-friendly chromatographic method to purify small regulatory RNAs.
Sex, Specimen part, Cell line, Subject
View SamplesThe maintenance of genome integrity is an essential trait to the successful transmission of genetic information. In animal germ cells, piRNAs guide PIWI proteins to silence transposable elements (TEs) in order to maintain genome integrity. In insects, most of TE silencing in the germline is achieved by secondary piRNAs that are produced by a feed-forward loop (the ping-pong cycle), which requires the piRNA-directed cleavages of two types of RNAs: mRNAs of functional euchromatic TEs and heterochromatic transcripts that contain defective TE sequences. The first cleavage which initiates such amplification loop remains poorly understood. Taking advantage of the existence of strains that are devoid of functional copies of the LINE-like I-element, we report that in such Drosophila ovaries, the initiation of a ping-pong cycle is achieved only by secondary I-element piRNAs that are produced in the ovary and deposited in the embryonic germline. This unusual secondary piRNA biogenesis, detected in the absence of functional I-element copies, results from the processing of sense and antisense transcripts of several different defective I-elements. Once acquired, for instance after ancestor aging, this capacity to produce heterochromatic-only secondary piRNAs is partially transmitted through generations via maternal piRNAs. Furthermore, such piRNAs acting as ping-pong initiators in a chromatin-independent manner confer to the progeny a high capacity to repress the I-element mobility. Our study explains at the molecular level the basis for epigenetic memory of maternal immunity that protects females from hybrid dysgenesis caused by transposition of paternally inherited functional I-elements. Overall design: Comparison of Drosophila small RNA populations in ovaries and/or eggs from 3-day-old or 25-day-old females.
piRNA-mediated transgenerational inheritance of an acquired trait.
Sex, Age, Specimen part, Cell line, Subject
View SamplesCortistatin A (CA) is a highly selective inhibitor of the Mediator kinases CDK8 and CDK19. Using CA, we report here the first large-scale identification of Mediator kinase substrates in human cells (HCT116). Among over 16,000 quantified phosphosites, we identified 78 high-confidence Mediator kinase targets within 64 proteins, including DNA-binding transcription factors and proteins associated with chromatin, DNA repair, and RNA polymerase II. Although RNA-Seq data correlated with Mediator kinase targets, CA effects on gene expression were limited and distinct from CDK8 or CDK19 knockdown. Quantitative proteome analyses, which tracked about 7,000 proteins across six time points (0 – 24h), revealed that CA selectively affected pathways implicated in inflammation, growth, and metabolic regulation; contrary to expectations, increased turnover of Mediator kinase targets was not generally observed. Collectively, these data support Mediator kinases as regulators of chromatin and RNA polymerase II activity and suggest cellular roles beyond transcription, including metabolism and DNA repair. Overall design: HCT116 cells were treated with either 100nM CA or DMSO in biological triplicate for each population (6 samples total). Treatment was for 24h for compound and vehicle.
Identification of Mediator Kinase Substrates in Human Cells using Cortistatin A and Quantitative Phosphoproteomics.
No sample metadata fields
View SamplesWe have generated a large collection of normal human mammary epithelial cell strains from women aged 16 to 91 years, derived from primary tissues, to enable functional and molecular interrogation of aging. We demonstrate in finite-lifespan cultured and uncultured epithelial cells that aging is associated with reduction of myoepithelial cells and with increases in luminal cells expressing keratin 14 and integrin 6, traits that are expressed exclusively in myoepithelial cells in women under 30. We find that changes to the luminal lineage result from age-dependent expansion of multipotent progenitors that bear defects resulting in incompletely differentiated luminal cells. These findings were verified in vivo in normal breast tissues. Myoepithelial cells have been suggested to act as tumor suppressors, and progenitor cells are implicated as the etiological roots of mammary carcinomas. Thus with aging there is a shift in the balance of luminal/myoepithelial lineages, and changes in the functional spectrum of multipotent progenitors, which presages increased potential for malignant transformation.
Accumulation of multipotent progenitors with a basal differentiation bias during aging of human mammary epithelia.
Age, Specimen part
View SamplesLaser capture microdissected choroid plexuses were obtained and expression arrays were generated to investigate gene expression in wt and ApoE choroid plexuses; the choroid plexus forms the cerebrospinal fluid, the cerebrospinal fliod barrier, functions as the major gateway for blood-born leukocytes to enter the brain in degenerative and inflammatory brain diseases, and the principal neuroimmune interface in the brain. We found lipid deposits in the aged choroid plexus of hyperlipidemic mice but none in the wt control choroid plexuses. Here, we studied the functional impact and gene epressions in wt and ApoE-deficient choroid plexuses.
ApoE attenuates unresolvable inflammation by complex formation with activated C1q.
Sex, Age, Specimen part
View SamplesThe overall goal of this project is to investigate the role of TGF-beta signaling in tissue-tissue interactions between myogenic precursors of craniofacial muscles and cranial neural crest cells (CNCCs). Here, we conducted gene expression profiling of the tongue bud from mice at embryonic day E13.5 with a CNCC-specific conditional inactivation of the TGF-beta receptor type 1 gene Alk5. These mice provide a model of microglossia as well as disrupted extraocular and masticatory muscle development, which are congenital birth defects commonly observed in several syndromic conditions.
ALK5-mediated transforming growth factor β signaling in neural crest cells controls craniofacial muscle development via tissue-tissue interactions.
Sex, Specimen part
View SamplesThe overall goal of this project is to investigate the role of TGF-beta signaling in tissue-tissue interactions between myogenic precursors of craniofacial muscles and cranial neural crest cells (CNCCs). Here, we conducted gene expression profiling of the mandibular arch from mice at embryonic day E11.5 with a CNCC-specific conditional inactivation of the TGF-beta receptor type 1 gene Alk5. These mice provide a model of microglossia as well as disrupted extraocular and masticatory muscle development, which are congenital birth defects commonly observed in several syndromic conditions.
ALK5-mediated transforming growth factor β signaling in neural crest cells controls craniofacial muscle development via tissue-tissue interactions.
Sex, Specimen part
View SamplesThe overall goal of this project is to investigate the role of TGF-beta signaling in tongue development in order to study the contribution of cranial neural crest (CNC) cells towards the patterning of cranial mesoderm for proper tongue formation. Here, we conducted gene expression profiling of embryonic tongue tissue from wild type mice as well as those with a neural crest specific conditional inactivation of the Tgfbr2 gene. The latter mice provide a model of microglossia, a common congenital birth defect which is frequently observed with several syndromic conditions.
Noncanonical transforming growth factor β (TGFβ) signaling in cranial neural crest cells causes tongue muscle developmental defects.
Sex, Specimen part
View SamplesThe overall goal of this project is to investigate the role of TGF-beta signaling in regulating the cellular metabolism of cranial neural crest (CNC) cells during palate development. Here, we conducted gene expression profiling of primary mouse embryonic palatal mesenchymal (MEPM) cells from wild type mice as well as those with a neural crest specific conditional inactivation of the Tgfbr2 gene. The latter mice provide a model of cleft palate, which is among the most common congenital birth defects and observed in many syndromic conditions.
Modulation of lipid metabolic defects rescues cleft palate in Tgfbr2 mutant mice.
Specimen part
View SamplesBackground: First- and third-generation retinoids are the main treatment in acne. Even though efficacious, they lack full selectivity for RAR expressed in the epidermis and infundibulum. Objectives: To characterize the in vitro metabolism and the pharmacology of the novel retinoid trifarotene. Methods: In vitro assays determined efficacy, potency and selectivity on RARs, as well as the activity on the expression of retinoid target genes in human keratinocytes and ex vivo cultured skin. In vivo studies investigated topical comedolytic, anti-inflammatory and depigmenting properties. The trifarotene-induced gene expression profile was investigated in non-lesional skin of acne patients and compared to ex vivo and in vivo models. Finally, the metabolic stability in human keratinocytes and hepatic microsomes was established. Results: Trifarotene is a selective RAR agonist with >20-fold selectivity over RAR and RAR. Trifarotene is active and stable in keratinocytes but rapidly metabolized by human hepatic microsomes, predicting improved safety. In vivo, trifarotene 0.01% applied topically is highly comedolytic and has antiinflammatory and antipigmenting properties. Gene expression studies indicated potent activation of known retinoid-modulated processes (epidermal differentiation, proliferation, stress response, RA metabolism) and novel pathways (proteolysis, transport/skin hydration, cell adhesion) in ex vivo and in vivo models, as well as in human skin after four weeks of topical application of trifarotene 0.005% cream. Conclusion: Based on its RAR selectivity, rapid degradation in human hepatic microsomes and pharmacological properties including potent modulation of epidermal processes, topical treatment with trifarotene is expected to provide strong efficacy combined with a favourable safety profile in acne and ichthyotic disorders.
Nonclinical and human pharmacology of the potent and selective topical retinoic acid receptor-γ agonist trifarotene.
Specimen part
View Samples