Project description:EGFR signaling controls skin development and homeostasis in mice and humans and its deficiency causes severe skin inflammation, which might affect epidermal stem cell behaviour. Here, we describe the inflammation-independent effects of EGFR-deficiency during skin morphogenesis and in adult HFSCs. Expression and alternative splicing analysis of RNAseq data from interfollicular epidermis and outer root sheath indicate that EGFR controls genes involved in epidermal differentiation, but also in centrosome function, DNA damage, cell cycle and apoptosis. Genetic experiments employing p53-deletion in EGFR–deficient epidermis reveal that EGFR signalling exhibits p53-dependent functions in proliferative epidermal compartments, as well as p53–independent functions in differentiated hair shaft keratinocytes. Loss of EGFR leads to absence of Lef1 protein specifically in the innermost epithelial hair layers, resulting in disorganization of medulla cells. Thus, our results uncover important spatial and temporal features of cell-autonomous EGFR functions in the epidermis.
Project description:EGFR targeted anti-cancer therapy induces severe skin toxicities, which affect life quality in patients. The lack of mechanistic details underlying these adverse events hampers their effective management. Here we identified EGFR as the epidermal master-regulator of the ERK pathway, which secures skin barrier integrity upon hair eruption. EGFR deficient epidermis displays a Th2-dominated expression signature and is permissive for excessive microbiota outgrowth. In the absence of EGFR, opening of the follicular ostia during hair eruption allows invasion of commensal microbiota aggravating barrier disruption and initiating an additional Th1 and Th17 response. Chronic folliculitis leads to Staphylococcus aureus dominated dysbiosis, further exacerbating inflammation and expanding barrier defects. Restoration of epidermal ERK signaling via therapeutic FGF7 treatment or transgenic SOS expression rescues skin barrier integrity in the absence of EGFR. These data reveal a gatekeeper function of the EGFR/ERK cascade in hair follicles securing the epidermal barrier around the erupting hair shaft.
Project description:Proteins of the human hair shaft contain a wealth of information about the coding regions of the person’s genome from whom the hair is derived. Commonly found at crime scenes, hair shafts may thus provide useful forensic evidence if the information they contain can be exploited. Present experiments show that hair shafts from four different anatomic sites are similarly useful in distinguishing individuals by protein profiling. However, the results demonstrated that protein profiles were dependent on anatomic site, indicating that a proper comparison requires matching the sites of origin. The differences in profile offer the prospect of determining the site of origin of hair by comparison with profiles of shafts from other anatomic sites. By contrast, the genetically variant peptides detected in the protein digests, that map to non-synonymous single nucleotide polymorphisms in subject DNA, were detectable regardless of the anatomic origin of the hair shafts. The resulting profiles of genetically variant peptides were more dependent on a subject’s genotype than on the anatomic origin of the hair shaft. Individual identification therefore can be based on peptide profiles regardless of body location. This study demonstrates the utility of proteomic analysis for increasing the forensic value of hair shaft evidence.
Project description:rationale: comparison of gene expression profiles in wildtype and Foxn1::dnFGFR2-IIIb transgenic hair follicles; identification of targets that mediate the effects seen in transgenic hair follicles; results: as already suggested by the phenotype, the molecular abnormalities appear to be restricted to the hair shaft medulla; Igfbp5 is an important mediator of transgene-dependent effects
Project description:rationale: comparison of gene expression profiles in wildtype and Foxn1::dnFGFR2-IIIb transgenic hair follicles; identification of targets that mediate the effects seen in transgenic hair follicles results: as already suggested by the phenotype, the molecular abnormalities appear to be restricted to the hair shaft medulla; Igfbp5 is an important mediator of transgene-dependent effects Keywords: ordered
Project description:Background: Despite that vitamins or their derivatives (Vits), such as panthenyl ethyl ether, tocopherol acetate, or pyridoxine have been widely used in topical hair care products, their efficacy and mode of action have been insufficiently studied. Objective: To elucidate biological influence of Vits on hair follicles and dissect underlying mechanisms. Methods: Mouse vibrissa hair follicle organ culture model was utilized to evaluate the effects of Vits on hair shaft elongation. Gene and protein expression analyses, and histological investigation were conducted to elucidate responsible mechanisms. Human hair follicle cell culture was adopted to assess clinical relevance. Results: In organ culture models, the combination of panthenyl ethyl ether, tocopherol acetate, and pyridoxine (namely PPT) supplementation significantly promoted hair shaft elongation. PPT-treatment enhanced hair matrix cell proliferation by 1.9 folds compared to controls, as demonstrated by Ki-67 positive immunoreactivity. PPT-treated mouse dermal papillae up-regulated Placental growth factor (Plgf) by 1.6 folds, compared to non-treated controls. Importantly, addition of PlGF neutralizing antibodies to the ex vivo culture diminished the promotive effect on hair growth and the increase in VEGFR1 phosphorylation achieved by PPT. A VEGFR1 inhibitor also repressed the promotion of hair shaft elongation. Microarray analysis suggested synergistic summation of individual Vit bioactivity, putatively explaining the effect of PPT. Moreover, PPT increased PlGF secretion in cultured human dermal papilla cells. Conclusion: Our findings suggested that PPT promoted hair shaft elongation via activating PlGF/VEGFR-1 signaling. The current study can shed light on the previously underrepresented advantage of utilizing Vits for ameliorating hair care products.
Project description:Hair shaft is one of the most common biological evidences found at crime scene. Due to the low amount and high degradation of nuclear DNA in hair shaft, it is difficult to achieve individual identification through routine method. The proteins in the hair shaft are stable and contain genetic polymorphisms in the form of single amino acid polymorphisms (SAPs), translated from non-synonymous single nucleotide polymorphisms (nsSNPs) in the genome.
Project description:This study examines the potential of hair shaft proteomic analysis to delineate genetic relatedness. Proteomic profiling and amino acid sequence analysis provide information for quantitative and statistically based analysis of individualization and sample similarity. Protein expression levels are a function of cell specific transcriptional and translational programs. These programs are greatly influenced by an individuals genetic background, and are therefore influenced by familial relatedness as well as ancestry and genetic disease. Proteomic profiles should therefore be more similar among related individuals than unrelated individuals. Likewise, profiles of genetically variant peptides that contain single amino acid polymorphisms, the result of non-synonymous SNP alleles, should behave similarly. The proteomically-inferred SNP alleles should also provide a basis for calculation of combined paternity and sibship indices. We test these hypotheses using matching proteomic and genetic datasets from a family of two adults and four siblings, one of which has a genetic condition that perturbs hair structure and properties. We demonstrate that related individuals, compared to those who are unrelated, have more similar proteomic profiles, profiles of genetically variant peptides and higher combined paternity indices and combined sibship indices. This study builds on previous analyses of hair shaft protein profiling and genetically variant peptide profiles in different real-world scenarios including different human hair shaft body locations and pigmentation status. It also validates the inclusion of proteomic information with other biomolecular substrates in forensic hair shaft analysis, including mitochondrial and nuclear DNA.
Project description:Here, Single-cell suspensions from the wavy wool and straight wool lambskins were prepared for unbiased single-cell RNA sequencing (scRNA-seq). Based on UAMP analysis, we identified 19 distinct populations from 15,830 single-cell transcriptomes and delineated their cellular identity from specific gene expression profiles. Furtherly, novel marker gene was applied in identifying dermal papilla cells isolated in vitro. By using pseudotime ordering analysis, we successfully constructed the epithelium cell lineage differentiation trajectory and revealed the dynamic gene expression profiles of matrix progenitors’ commitment to the hair shaft and inner root sheath (IRS) cells. Meanwhile, intercellular communication between different cell populations was inferred based on CellChat and the priori knowledge of ligand-receptor pairs, as a result strong intercellular communication and associated signaling pathways were revealed. Besides, to clarify the molecular mechanism of wool curvature, differentially expressed genes in specific cells between straight wool and curly wool were identified and analyzed. Our findings here provide unbiased and systematic view of transcriptional organization of sheep hair follicle, reveal the differentiation and spatial signatures underlying sheep hair follicle heterogeneity and wool curvature, which will provide a valuable resource for understanding the molecular pathways involved in sheep hair follicle development.