Project description:Cockayne syndrome B (CSB) protein is a member of the SWI/SNF family and has DNA-dependent ATPase and ATP-dependent chromatin remodeling activities. The CSB protein is missing or altered in CS-B cells. CS-B cells are hypersensitive to UV light and defective in transcription-coupled DNA repair (TCR). TCR efficiently removes a variety of lesions from the transcribed strand of active genes. It has been shown that lesions specifically in the transcribed strand of active genes trigger the induction of apoptosis following UV irradiation. Several DNA damage signaling cascades, including the ATR/Chk1, p38 kinase, p53, and jun N-terminal kinase pathways are activated following UV irradiation. However, the role of TCR in cellular global transcriptional responses to UV irradiation remains to be elucidated. Using oligonucleotide microarray technology, we analyzed the time course of responses of CS-B cells (CS-B) and CS-B cells complemented with wild-type CSB cDNA (CS-B wt). Keywords: UV response, time course, disease state analysis
Project description:Cockayne syndrome B (CSB) protein is a member of the SWI/SNF family and has DNA-dependent ATPase and ATP-dependent chromatin remodeling activities. The CSB protein is missing or altered in CS-B cells. CS-B cells are hypersensitive to UV light and defective in transcription-coupled DNA repair (TCR). TCR efficiently removes a variety of lesions from the transcribed strand of active genes. It has been shown that lesions specifically in the transcribed strand of active genes trigger the induction of apoptosis following UV irradiation. Several DNA damage signaling cascades, including the ATR/Chk1, p38 kinase, p53, and jun N-terminal kinase pathways are activated following UV irradiation. However, the role of TCR in cellular global transcriptional responses to UV irradiation remains to be elucidated. Using oligonucleotide microarray technology, we analyzed the time course of responses of CS-B cells (CS-B) and CS-B cells complemented with wild-type CSB cDNA (CS-B wt). Experiment Overall Design: In order to investigate the global transcriptional responses to UV damage in TCR-proficient or TCR-deficient cells, CS-B wt and CS-B cells were irradiated with 10 J/m2 of UV light and incubated for 2 or 12 hours. All experiments were performed in triplicate.
Project description:UV irradiation is a major environmental effector of skin damage and aging. Elevated levels of glycosaminoglycans (GAGs), as measured by Hale’s stain, are seen following cutaneous photodamage. Preliminary data from our lab indicates that this is a complex response involving differential regulation of both GAGs and proteoglycans. Recently, different GAG species have been shown to have distinct effects on the recruitment and activation of immune cells and stimulation of cytokine production (Taylor and Gallo, FASEB, 2006; 20: 9-22). We speculate that the elevated GAGs and proteoglycans observed after ultraviolet B (UVB) irradiation are involved in the inflammatory and healing responses to photodamage. Chondroitin sulfate synthases (CSSs) are not increased by UVB in mice or in cultured human fibroblasts. To determine whether genomic upregulation of CSSs is responsible for the post-UVB CS increase, we measured the dermal expression of CSS1 and CSS3 mRNA in C57Bl6 mice after 5 days of UV-B exposure. Irradiation caused no change in either CSS1 or CSS3 mRNA expression. We also studied CSS RNA expression in cultured human fibroblasts. We compared control cells to cells treated with 30 mJ/cm2 UVB, cells treated with 1 ng/mL IL-1α, and cells co-stimulated with UVB and IL-1α. In vivo, UV-B induces IL-1α production by keratinocytes and inflammatory cells, and this IL-1α interacts with fibroblasts. Co-stimulation with IL-1α + UVB induces TNF-α production by the fibroblasts, mirroring the in vivo interaction. CSS1 mRNA was suppressed 60% and CSS3 mRNA expression dropped 87% relative to sham at 24 hours post-treatment (p<0.001, Dunnet q’). Since CS is not upregulated by its synthases, we postulated an alternative mode of induction whereby one or more CS proteoglycans are transcriptionally increased and bind more CS in the dermis. We used the N-13 goat monoclonal anti-serglycin antibody to visualize changes in cutaneous serglycin content following acute UV-B exposure. Serglycin is one example of CS-binding dermal proteoglycans that is induced by UVB, and there are likely others. Diffuse upper-dermal serglycin staining, like upper-dermal CS, was induced continuously at 24, 48, and 72 hours after irradiation. Serglycin-expressing inflammatory cells are recruited to the dermis following irradiation, peaking at 48 hours post-exposure. A statistically significant 1.70 fold increase in serglycin mRNA was measured in cultured human fibroblasts 6 hours after co-stimulation with UVB and IL-1α. Realtime PCR also revealed a significant 2.04 fold upregulation at 24 hours after co-stimulation, and serglycin was increased 4.63 times 6 hours after Il-1α treatment alone.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Purpose: Light is one of the most important environmental signal that affects the physiology and action of Volvox carteri. However, there are limited reports about the effects of UV-B irradiation on genome-wide transcriptional regulation in this organism. We surveyed the overall transcriptional responses of somatic and reproductive cells to UV-B irradiation using RNA-seq data. Methods: The somatic and reproductive cells were separated. The cell-types were treated for one hour by low-doses UV-B irradiation. Three biological replicates per cell-types (totally 12 samples) were used for RNA extraction. High-throughput RNA sequencing performed with separated-cells samples. Sequencing runs were performed on an Illumina HiSeq-2500. Transcriptome analysis was carried out in order to elucidate the effect of UV-B irradiation on whole transcriptional modification of physiological mechanisms. Results: In total, 264 and 272 million clean reads were produced in somatic and reproductive cells, respectively. The results showed that, as compared to control group, there were no differentially expressed genes in reproductive cells under treatment. However, treating the somatic cells with UV-B irradiation resulted in 126 differential genes as compared to untreated control group. Our results showed that there is light-specific transcriptional regulation in this organism. So that, different pathways were co-regulated by UV-B irradiation via the transcriptional regulation of genes encoding key enzymes in these pathways. Conclusions: Our findings showed that low UV-B irradiation influence on the cell-type specific gene expression. The findings of this study may present new insights to understand responsive mechanisms to UV-B irradiation by modulating expression of cell-type specific in the V. carteri.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression. Two-condition experiment, Normoxic MSCs vs. Hypoxic MSCs.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.