Project description:Exposure to ultraviolet (UV) irradiation is the major cause of nonmelanoma skin cancer, the most common form of cancer in the United States. UV irradiation has a variety of effects on the skin associated with carcinogenesis, including DNA damage and effects on signal transduction. The alterations in signaling caused by UV regulate inflammation, cell proliferation, and apoptosis. UV also activates the orphan receptor tyrosine kinase and proto-oncogene Erbb2 (HER2/neu). In this study, we demonstrate that the UV-induced activation of Erbb2 regulates the response of the skin to UV. Inhibition or knockdown of Erbb2 before UV irradiation suppressed cell proliferation, cell survival, and inflammation after UV. In addition, Erbb2 was necessary for the UV-induced expression of numerous proinflammatory genes that are regulated by the transcription factors nuclear factor-kappaB and Comp1, including interleukin-1beta, prostaglandin-endoperoxidase synthase 2 (Cyclooxygenase-2), and multiple chemokines. These results reveal the influence of Erbb2 on the UV response and suggest a role for Erbb2 in UV-induced pathologies such as skin cancer. Keywords: time course, ultraviolet irradiation, UV, erbB2, mouse skin
Project description:Exposure to ultraviolet (UV) irradiation is the major cause of nonmelanoma skin cancer, the most common form of cancer in the United States. UV irradiation has a variety of effects on the skin associated with carcinogenesis, including DNA damage and effects on signal transduction. The alterations in signaling caused by UV regulate inflammation, cell proliferation, and apoptosis. UV also activates the orphan receptor tyrosine kinase and proto-oncogene Erbb2 (HER2/neu). In this study, we demonstrate that the UV-induced activation of Erbb2 regulates the response of the skin to UV. Inhibition or knockdown of Erbb2 before UV irradiation suppressed cell proliferation, cell survival, and inflammation after UV. In addition, Erbb2 was necessary for the UV-induced expression of numerous proinflammatory genes that are regulated by the transcription factors nuclear factor-kappaB and Comp1, including interleukin-1beta, prostaglandin-endoperoxidase synthase 2 (Cyclooxygenase-2), and multiple chemokines. These results reveal the influence of Erbb2 on the UV response and suggest a role for Erbb2 in UV-induced pathologies such as skin cancer. Keywords: time course, ultraviolet irradiation, UV, erbB2, mouse skin The dorsal skin of adult female CD-1 mice was clipped one day before treatment and shaved on the day of treatment. DMSO or 4 mg AG825 dissolved in DMSO was applied topically to the shaved back of the mice 2 h prior to exposure to 10 kJ/m^2 UV or sham irradiation. The UV dose was approximately 30% UVA, 70% UVB and <1% UVC, with a total output of 470 uW/cm^2. Flash frozen skin was removed and total RNA expracted with TRIzol reagent (Invitrogen) and further purified with an RNeasy kit (Qiagen). Amplification, reverse-transcription, biotinylation, and hybridization were all carried out under standard conditions and procedures recommended by the manufacturer.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:Purpose: to explore the function and mechanism of skin damage induced by ultraviolet irradiation. Method: Skin tRF & tiRNA profiles of mice normal skin and damage skin induced by Ultraviolet Irradiation (UV) were generated by deep sequencing, using Illumina NextSeq 500. qRT–PCR validation was performed using SYBR Green assays. Results:Sequencing was used to screen expression profiles and predict target genes. Compared with normal skin, a total of 31 differentially expressed tRFs and tiRNAs were screened. Among these, 10 tRFs and tiRNAs were shown to be significantly different in expression levels, where there were 4 up-regulated and 6 down-regulated target genes.Altered expression of 4 genes was confirmed with qRT–PCR, demonstrating the high degree of sensitivity of the RNA-seq method. Hierarchical clustering of differentially expressed genes uncovered several as yet uncharacterized genes that may contribute to skin repair after damage induced by ultraviolet irradiation. Conclusion: tRF-Trp-TCA-001 and tRF-Gly-CCC-019 plays an important role in acute skin injury induced by UVB radiation by regulating the ras-related C3 botulinum toxin substrate 1 (Rac1) gene in the WNT signaling pathway. This study provides new insights into the mechanisms and therapeutic targets of UV-induced skin injury.
Project description:Intense ultraviolet (UV) exposure can cause phototoxic reactions, such as skin inflammation, resulting in injury. UV is believed to be the direct cause of DNA damage, but the mechanisms of transcriptional regulation within cells after DNA damage are unclear. The bioinformatic analysis of transcriptome sequencing data from UV-irradiated and non-UV-irradiated skin showed that transcription-related proteins, such as HSF4 and COIL, mediate the cellular response to UV irradiation. HSF4 and COIL could form a complex under UV irradiation, and the preference for binding target genes changed. This is due to the presence of a large number of R-loops in the cells under UV irradiation and the ability of COIL to recognize the R-loops. The regulation of target genes was altered by the HSF4-COIL complex, and the expression of inflammation and aging-related genes, such as ATG7, TFPI, and LIMS1, were enhanced. A drug screen was performed for the recognition sites of COIL and R-loop. N6-(2-hydroxyethyl)-adenosine (HEA) could competitively bind COIL and inhibit the binding of COIL to R-loop. Thus, the activation of downstream inflammation-related genes and inflammatory skin injury were inhibited.
Project description:Translational research is commonly performed in the C57B6/J mouse strain, chosen for its genetic homogeneity and phenotypic uniformity. Here, we evaluate the suitability of the white-footed deer mouse (Peromyscus leucopus) as a model organism for aging research, offering a comparative analysis against C57B6/J and diversity outbred (DO) Mus musculus strains. Our study includes comparisons of body composition, skeletal muscle function, and cardiovascular parameters, shedding light on potential applications and limitations of P. leucopus in aging studies. Notably, P. leucopus exhibits distinct body composition characteristics, emphasizing reduced muscle force exertion and a unique metabolism, particularly in fat mass. Cardiovascular assessments showed changes in arterial stiffness, challenging conventional assumptions and highlighting the need for a nuanced interpretation of aging-related phenotypes. Our study also highlights inherent challenges associated with maintaining and phenotyping P. leucopus cohorts. Behavioral considerations, including anxiety-induced responses during handling and phenotyping assessment, pose obstacles in acquiring meaningful data. Moreover, the unique anatomy of P. leucopus necessitates careful adaptation of protocols designed for Mus musculus. While showcasing potential benefits, further extensive analyses across broader age ranges and larger cohorts are necessary to establish the reliability of P. leucopus as a robust and translatable model for aging studies.
Project description:Ultraviolet-B (UVB) irradiation of the skin was performed on rat (skin and DRG) and human (skin) tissue. The resulting changes in gene expression were then profiled by using RNA-seq to compare gene expression between irradiated and non-irradiated samples
Project description:BackgroundCopy number variation is an important dimension of genetic diversity and has implications in development and disease. As an important model organism, the mouse is a prime candidate for copy number variant (CNV) characterization, but this has yet to be completed for a large sample size. Here we report CNV analysis of publicly available, high-density microarray data files for 351 mouse tail samples, including 290 mice that had not been characterized for CNVs previously.ResultsWe found 9634 putative autosomal CNVs across the samples affecting 6.87% of the mouse reference genome. We find significant differences in the degree of CNV uniqueness (single sample occurrence) and the nature of CNV-gene overlap between wild-caught mice and classical laboratory strains. CNV-gene overlap was associated with lipid metabolism, pheromone response and olfaction compared to immunity, carbohydrate metabolism and amino-acid metabolism for wild-caught mice and classical laboratory strains, respectively. Using two subspecies of wild-caught Mus musculus, we identified putative CNVs unique to those subspecies and show this diversity is better captured by wild-derived laboratory strains than by the classical laboratory strains. A total of 9 genic copy number variable regions (CNVRs) were selected for experimental confirmation by droplet digital PCR (ddPCR).ConclusionThe analysis we present is a comprehensive, genome-wide analysis of CNVs in Mus musculus, which increases the number of known variants in the species and will accelerate the identification of novel variants in future studies.
Project description:BackgroundLong terminal repeat (LTR) retrotransposons make up a large fraction of the typical mammalian genome. They comprise about 8% of the human genome and approximately 10% of the mouse genome. On account of their abundance, LTR retrotransposons are believed to hold major significance for genome structure and function. Recent advances in genome sequencing of a variety of model organisms has provided an unprecedented opportunity to evaluate better the diversity of LTR retrotransposons resident in eukaryotic genomes.ResultsUsing a new data-mining program, LTR_STRUC, in conjunction with conventional techniques, we have mined the GenBank mouse (Mus musculus) database and the more complete Ensembl mouse dataset for LTR retrotransposons. We report here that the M. musculus genome contains at least 21 separate families of LTR retrotransposons; 13 of these families are described here for the first time.ConclusionsAll families of mouse LTR retrotransposons are members of the gypsy-like superfamily of retroviral-like elements. Several different families of unrelated non-autonomous elements were identified, suggesting that the evolution of non-autonomy may be a common event. High sequence similarity between several LTR retrotransposons identified in this study and those found in distantly-related species suggests that horizontal transfer has been a significant factor in the evolution of mouse LTR retrotransposons.