Telogen is not simply a quiescent part of the hair cycle
Identification of telogen markers underscores that telogen is far from a quiescent hair cycle phase.
Sex
View SamplesSince hair growth disorders can carry a major psychological burden, more effective human hair growth-modulatory agents need to be urgently developed. Here, we used the hypertrichosis-inducing immunosuppressant, cyclosporine A (CsA), as a lead compound to identify new hair growth-promoting targets. Through microarray analysis we identified the Wnt inhibitor, SFRP1, as being downregulated in the dermal papilla (DP) of CsA-treated human scalp hair follicles (HFs) ex vivo. Therefore, we further investigated the function of SFRP1 using a pharmacological approach and found that SFRP1 regulates intrafollicular canonical Wnt/-catenin activity through inhibition of Wnt ligands in the human hair bulb. Conversely, inhibiting SFRP1 activity through the SFRP1 antagonist, WAY-316606, enhanced hair shaft production, hair shaft keratin expression and inhibited spontaneous HF regression (catagen) ex vivo. Collectively, these data (a) identify Wnt signaling as a novel, non-immune-inhibitory CsA target; (b) introduce SFRP1 as a physiologically important regulator of canonical -catenin activity in a human (mini-)organ; and (c) demonstrate WAY-316606 to be a promising new promoter of human hair growth. Since inhibiting SFRP1 only facilitates Wnt signaling through ligands that are already present, this ligand-limited therapeutic strategy for promoting human hair growth may circumvent potential oncological risks associated with chronic Wnt over-activation.
Identifying novel strategies for treating human hair loss disorders: Cyclosporine A suppresses the Wnt inhibitor, SFRP1, in the dermal papilla of human scalp hair follicles.
Sex, Specimen part, Treatment
View SamplesHair follicles undergo recurrent cycling of controlled growth (anagen), regression (catagen), and relative quiescence (telogen) with a defined periodicity. Taking a genomics approach to study gene expression during synchronized mouse hair follicle cycling, we discovered that, in addition to circadian fluctuation, CLOCK-regulated genes are also modulated in phase with the hair growth cycle. During telogen and early anagen, circadian clock genes are prominently expressed in the secondary hair germ, which contains precursor cells for the growing follicle. Analysis of Clock and Bmal1 mutant mice reveals a delay in anagen progression, and the secondary hair germ cells show decreased levels of phosphorylated Rb and lack mitotic cells, suggesting that circadian clock genes regulate anagen progression via their effect on the cell cycle. Consistent with a block at the G1 phase of the cell cycle, we show a significant upregulation of p21 in Bmal1 mutant skin. While circadian clock mechanisms have been implicated in a variety of diurnal biological processes, our findings indicate that circadian clock genes may be utilized to modulate the progression of non-diurnal cyclic processes.
Circadian clock genes contribute to the regulation of hair follicle cycling.
Sex
View SamplesHair follicles undergo recurrent cycling of controlled growth (anagen), regression (catagen), and relative quiescence (telogen) with a defined periodicity. Taking a genomics approach to study gene expression during synchronized mouse hair follicle cycling, we discovered that, in addition to circadian fluctuation, CLOCK-regulated genes are also modulated in phase with the hair growth cycle. During telogen and early anagen, circadian clock genes are prominently expressed in the secondary hair germ, which contains precursor cells for the growing follicle. Analysis of Clock and Bmal1 mutant mice reveals a delay in anagen progression, and the secondary hair germ cells show decreased levels of phosphorylated Rb and lack mitotic cells, suggesting that circadian clock genes regulate anagen progression via their effect on the cell cycle. Consistent with a block at the G1 phase of the cell cycle, we show a significant upregulation of p21 in Bmal1 mutant skin. While circadian clock mechanisms have been implicated in a variety of diurnal biological processes, our findings indicate that circadian clock genes may be utilized to modulate the progression of non-diurnal cyclic processes.
Circadian clock genes contribute to the regulation of hair follicle cycling.
Sex, Specimen part
View SamplesHair follicles undergo recurrent cycling of controlled growth (anagen), regression (catagen), and relative quiescence (telogen) with a defined periodicity. Taking a genomics approach to study gene expression during synchronized mouse hair follicle cycling, we discovered that, in addition to circadian fluctuation, CLOCK-regulated genes are also modulated in phase with the hair growth cycle. During telogen and early anagen, circadian clock genes are prominently expressed in the secondary hair germ, which contains precursor cells for the growing follicle. Analysis of Clock and Bmal1 mutant mice reveals a delay in anagen progression, and the secondary hair germ cells show decreased levels of phosphorylated Rb and lack mitotic cells, suggesting that circadian clock genes regulate anagen progression via their effect on the cell cycle. Consistent with a block at the G1 phase of the cell cycle, we show a significant upregulation of p21 in Bmal1 mutant skin. While circadian clock mechanisms have been implicated in a variety of diurnal biological processes, our findings indicate that circadian clock genes may be utilized to modulate the progression of non-diurnal cyclic processes.
Circadian clock genes contribute to the regulation of hair follicle cycling.
Sex, Specimen part
View SamplesMale fertility and testis function changes with age and so it was sought to determine if these changes are accompanied by changes in gene expression.
Aging results in differential regulation of DNA repair pathways in pachytene spermatocytes in the Brown Norway rat.
Specimen part
View SamplesThe root apex is an important section of the plant root, involved in environmental sensing and cellular development. Analyzing the gene profile of root apex in diverse environments is important and challenging, especially when the samples are limiting and precious, such as in spaceflight. The feasibility of using tiny root sections for transcriptome analysis was examined in this study.To understand the gene expression profiles of the root apex, Arabidopsis thaliana Col-0 roots were sectioned into Zone-I (0.5 mm, root cap and meristematic zone) and Zone-II (1.5 mm, transition, elongation and growth terminating zone). Gene expression was analyzed using microarray and RNA seq.Both the techniques, arrays and RNA-Seq identified 4180 common genes as differentially expressed (with > two-fold changes) between the zones. In addition, 771 unique genes and 19 novel TARs were identified by RNA-Seq as differentially expressed which were not detected in the arrays. Single root tip zones can be used for full transcriptome analysis; further, the root apex zones are functionally very distinct from each other. RNA-Seq provided novel information about the transcripts compared to the arrays. These data will help optimize transcriptome techniques for dealing with small, rare samples. Overall design: Arabidopsis thaliana var. Columbia (COL-0) seedlings were grown on sterile solid media plates containing 0.5 % phytagel. The plates were vertically placed in growth chambers with continuous light (80-100 µmol m -2) at a constant temperature of 19° C. Eight day old seedlings were harvested into RNA-later solution in a 50 mL centrifuge tubes and stored at -20 °C freezer. The root tips were dissected into zone-I: 0.5mm from the tip including the root cap and root division zones, and zone-II: 1.5mm sections including root elongation and root hair zone. Microarray and sequencing experiments were performed.
Comparing RNA-Seq and microarray gene expression data in two zones of the <i>Arabidopsis</i> root apex relevant to spaceflight.
Age, Specimen part, Subject
View SamplesStressors may have negative or positive effects in dependence of the dose (hormesis). We studied this phenomenon in Caenorhabditis elegans by applying weak or severe abiotic (cadmium, CdCl2) and/or biotic stress (different bacterial diets) during cultivation/breeding of the worms, and determining developmental speed or survival rates and performing transcriptome profiling and RT-qPCR analyses to explore the genetic basis of the detected phenotypic differences. This study showed that a bacterial diet resulting in higher levels of energy resources in the worms (E. coli OP50 feeding) or weak abiotic and biotic stress especially promote the resistance against severe abiotic or biotic stress and the age-specific survival rate of WT. Overall design: Five experimental conditions; mostly three replicates per experimental condition; four contrasts between test and control conditions functionally analyzed.
Bacterial diet and weak cadmium stress affect the survivability of <i>Caenorhabditis elegans</i> and its resistance to severe stress.
Cell line, Treatment, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Comparing RNA-Seq and microarray gene expression data in two zones of the <i>Arabidopsis</i> root apex relevant to spaceflight.
Age, Specimen part
View SamplesThe root apex is an important section of the plant root, involved in environmental sensing and cellular development. Analyzing the gene profile of root apex in diverse environments is important and challenging, especially when the samples are limiting and precious, such as in spaceflight. The feasibility of using tiny root sections for transcriptome analysis was examined in this study.To understand the gene expression profiles of the root apex, Arabidopsis thaliana Col-0 roots were sectioned into Zone-I (0.5 mm, root cap and meristematic zone) and Zone-II (1.5 mm, transition, elongation and growth terminating zone). Gene expression was analyzed using microarray and RNA seq.Both the techniques, arrays and RNA-Seq identified 4180 common genes as differentially expressed (with > two-fold changes) between the zones. In addition, 771 unique genes and 19 novel TARs were identified by RNA-Seq as differentially expressed which were not detected in the arrays.
Comparing RNA-Seq and microarray gene expression data in two zones of the <i>Arabidopsis</i> root apex relevant to spaceflight.
Age, Specimen part
View Samples