Project description:Bald thigh syndrome is a common hair loss disorder in sighthounds. The overall goal of our study was to identify the cause of bald thigh syndrome and the pathological changes associated with it. We approached this aim by comparing skin biopsies and hair shafts of affected and control dogs microscopically as well as by applying high-throughput technologies such as genomics, transcriptomics and proteomics. While the histology is rather unspecific in most cases, trichogram analysis and scanning electron microscopy revealed severe structural abnormalities in hair shafts of affected dogs. This finding is supported by the results of the transcriptomic and proteomic profiling of skin biopsies and hair shafts, respectively, where genes and proteins important for differentiation of the inner root sheath and the assembly of a proper hair shaft were downregulated. Transcriptome profiling of skin biopsies revealed a downregulation of genes encoding 23 hair shaft keratins and 51 keratin associated proteins, as well as desmosomal cadherins and several actors of the BMP signaling pathway, which is important for hair shaft differentiation. To identify differentially expressed proteins in structural abnormal hair shafts, we performed nLC-MS/MS- based proteomic analysis of fractured hair shafts of four dogs with bald thigh syndrome (Greyhounds, n=3, Whippet, n=1) and intact telogen hair shafts of four control dogs (Greyhounds, n=3, Whippet= n=1) plucked on the thighs. Decreased expression of keratin 71 and desmocollin 2 on the mRNA level in skin biopsies corresponded with a reduced protein expression in the hair shafts of affected dogs.
Project description:In a transcriptome study of psoriatic (PP) vs. normal (NN) skin, we found a co-expressed gene module (N5) enriched 11.5-fold for lipid biosynthetic genes. We also observed fewer visible hairs in PP skin, compared to uninvolved (PN) or NN skin (p<0.0001). To ask whether these findings might be due to abnormalities of the pilosebaceous unit, we carried out 3D morphometric analysis of paired PP and PN biopsies. Sebaceous glands (SG) were markedly atrophic in PP vs. PN skin (91% average reduction in volume, p=0.031). Module N5 genes were strongly downregulated in PP vs. NN skin (fold-change [FC] < 0.25, 44.4-fold), and strongly up-regulated in sebaceous hyperplasia (SH, FC > 4, 54.1-fold). The intersection of PP-downregulated and SH-upregulated gene lists generated a gene expression signature consisting solely of module N5 genes, whose expression in PP vs. NN skin was inversely correlated with the signature of IL17-stimuated keratinocytes. Despite loss of visible hairs, morphometry identified elongated follicles in PP vs. PN skin (average 1.7 vs. 1.2 Jm, p=0.020). These results document SG atrophy in non-scalp psoriasis, identify a cytokine-regulated set of SG signature genes, and suggest that loss of visible hair in PP skin may result from abnormal SG function.
Project description:In the present study transcriptomic profiling of skin biopsies containing secondary hair follicles were utilized to identify key genes and signaling pathways involved in hair follicle transition from no-growth phase (telogen) to growth phase (anagen).
Project description:EGFR/MEK inhibitor therapy induces a distinct inflammatory hair follicle response that includes a collapse of hair follicle immune privilege and differential modulation of IL-33 and IL-37 expression. Our findings suggest that successful future management of EGFRi/MEKi-induced folliculitis requires restoration of hair follicle immune privilege. In this RNAseq parietal scalp (rather than truncal skin) biopsies were taken from long-term (3-9 months) EGFRi-treated patients exhibiting folliculitis (Chronic-EGFRi) or from patients prior to commencing and after two weeks of EGFRi therapy (Acute-EGFRi), compared to normal scalp skin.
Project description:In a transcriptome study of psoriatic (PP) vs. normal (NN) skin, we found a co-expressed gene module (N5) enriched 11.5-fold for lipid biosynthetic genes. We also observed fewer visible hairs in PP skin, compared to uninvolved (PN) or NN skin (p<0.0001). To ask whether these findings might be due to abnormalities of the pilosebaceous unit, we carried out 3D morphometric analysis of paired PP and PN biopsies. Sebaceous glands (SG) were markedly atrophic in PP vs. PN skin (91% average reduction in volume, p=0.031). Module N5 genes were strongly downregulated in PP vs. NN skin (fold-change [FC] < 0.25, 44.4-fold), and strongly up-regulated in sebaceous hyperplasia (SH, FC > 4, 54.1-fold). The intersection of PP-downregulated and SH-upregulated gene lists generated a gene expression signature consisting solely of module N5 genes, whose expression in PP vs. NN skin was inversely correlated with the signature of IL17-stimuated keratinocytes. Despite loss of visible hairs, morphometry identified elongated follicles in PP vs. PN skin (average 1.7 vs. 1.2 Jm, p=0.020). These results document SG atrophy in non-scalp psoriasis, identify a cytokine-regulated set of SG signature genes, and suggest that loss of visible hair in PP skin may result from abnormal SG function. Gene expression was compared between sebaceous hyperplasia lesions (n = 5) and normal skin (n = 3) from control subjects.
Project description:We established a culture method of human keratinocytes from the bulge region of a plucked hair follicle, that contains multipotent epithelial stem cells with high proliferative potential. Using our method, keratinocyte cultures were successfully obtained from all subjects without invasive skin biopsies. We compared the gene expression profiles between the cultured keratinocytes derived from human hair-follicle-bulge (bulgeM-bM-^@M-^Sderived keratinocytes; BDKs) and neonatal human epidermal keratinocytes (NHEKs), and between BDKs from donors with atopic dermatitis and non-atopic controls using microarray analysis. Keywords: expressin profiling Two cell cultures, BDK vs. NHEK cells. 18 BDKs; derived from eighteen healthy volunteers , 6 NHEKs; purchased from Kurabo (Osaka, Japan). One replicate per array.
Project description:Alopecia areata (AA) is a prevalent disease associated with major emotional distress, and lacks effective, safe therapeutics for patients with extensive hair loss. This is the first report of hair regrowth with specific cytokine antagonism, in three patients with extensive hair loss ranging from 40% scalp involvement to alopecia universalis. Ustekinumab, an IL-12/23p40 antagonist that is highly effective in psoriasis, showed impressive ability to induce hair regrowth, coupled with suppression of inflammatory pathways and upregulation of hair keratins. Our report suggests that extensive AA is reversible using targeted treatments, opening the door for specific cytokine antagonism for this debilitating disease. We evaluated hair regrowth in three AA patients at 20 weeks after treatment with 3 subcutaneous doses of 90mg ustekinumab given at weeks 0, 4, and 16. Skin biopsies of lesional and non-lesional scalp (when available) were taken at baseline (week 0) and at week 20. We also obtained biopsies from three healthy individuals.