|Year : 2011 | Volume
| Issue : 3 | Page : 28-29
Session N: Cicatricial Alopecia and Stem Cells
|Date of Web Publication||16-Jun-2011|
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
. Session N: Cicatricial Alopecia and Stem Cells. Int J Trichol 2011;3, Suppl S1:28-9
Hormonal regulation of human hair follicle epithelial stem cell functions in situ and in vitro
Stephan Tiede 1 *, Yuval Ramot 1, 2 , Katrin Bohm 1 , Christian Plate 1 , Ralf Paus 1, 3
1 Department of Dermatology, University of Lübeck, Lübeck, Germany; 2 Department of Dermatology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel; 3 School of Translational Medicine, University of Manchester, Manchester, UK.
The hormonal controls of adult epithelial hair follicle (HF) stem cells (eHFSCs) are largely unknown. Here, we investigated (neuro-) endocrine controls of normal adult human eHFSCs as a model to characterize these controls in situ and in vitro. By using K15-promoter-driven GFP expression, demarcating epithelial HF progenitors, we investigated the influence of prolactin (PRL), thyroid hormones (THs), and calcitriol on selected eHFSCs functions. We found that PRL up regulated K15-promoter activity in the HF bulge region, additionally extended the area of K15-expression beyond the bulge region and stimulated K15 protein expression. THs up regulated K15-promoter activity, K15 transcription and protein expression in eHFSCs. Moreover, THs reduced the colony forming efficiency (CFE), proliferation, viability and induced apoptosis in cultured K15-GFP+ progenitors. THs may also induce epithelial-mesenchymal-transition, indicated by fibroblastoid morphology and up regulated expression of vimentin and of the immuno-inhibitory eHFSCs marker CD200 in situ and in vitro. Calcitriol induced morphological changes, up-regulated vitamin-D-receptor and CD200 expression and impaired both CFE and proliferation. We documented that human eHFSCs underlie prominent (neuro-)endocrine controls, not only by classical steroid hormones but also by peptide neurohomones. This encourages one to systematically explore the impact of these hormonal controls on human eHFSCs in situ and in vitro and to explore how these may be clinically exploited.
Wounding re-programs hair follicle stem cell progeny and promotes tumorigenesis
Maria Kasper* +1 , Viljar Jaks* +1, 2 , Åsa Bergström 1 , Alexandra Are 1 , Rune Toftgård 1
1 Department of Biosciences and Nutrition, Karolinska Institute, Center for Biosciences, SE-141 83 Huddinge, Sweden; 2 University of Tartu, Institute for Molecular and Cell Biology, Tartu, Estonia.
*E-mail: Maria.Kasper@ki.se; Viljar.Jaks@ki.se
+ These authors contributed equally
Chronic and acute wounds constitute a well-established risk factor for development of epithelial-derived skin tumours although the underlying mechanisms are largely unknown. Basal Cell Carcinomas (BCC) are the most common skin cancers displaying a number of features reminiscent of hair follicle (HF) and are dependent on deregulated Hedgehog (Hh)/GLI signaling. Here we show, in a mouse model conditionally expressing GLI1 and in a model with homozygous inactivation of Ptch1, mimicking the situation in human BCCs, that the wound environment strongly accelerates the formation of BCC-like lesions. Lineage tracing reveals that the Lgr5+ SC residing in the bulge and the secondary hair germ in telogen, represents a cell of origin for tumour formation associated with the HF, and in combination with wounding also for BCC-like lesions associated with the interfollicular epidermis (IFE). We conclude that the wound environment allows repopulation of the permanent part of the HF and the IFE by follicular Lgr5+ progeny and induces their reprogramming to a stem cell-like state enhancing BCC development, thereby establishing a link between skin wounds and cancer risk.
Histopathological and clinical findings in frontal fibrosing alopecia: A report of 70 cases
David A. Whiting
The hair & skin research and treatment center, Dallas, Texas, USA.
Frontal fibrosing alopecia (FFA) was first reported in 6 postmenopausal females in 1994 by Steven Kossard in Sydney, Australia. It is characterized by a broadening symmetrical band of cicatricial alopecia involving the frontal and often temporal hairlines. Scarring alopecia of the eyebrows may precede, accompany or follow this process. The first 2 patients with FFA were seen in Baylor Hair Clinic in 2003. 70 biopsies from patients with this disease were studied by February 2011, 59 from this clinic and 11 from other sites. 4 mm punch biopsies were submitted in 10% formalin, sectioned horizontally and stained with hematoxylin and eosin. The patients comprised 68 females and 2 males, average age 63 (range 47-81) years, mostly Whites but including Hispanics, Blacks and Asiatics. Areas of lichen planopilaris were found elsewhere on the scalp in 30% of cases. Most patients were seen with advanced disease, reflecting chronic rather than acute changes. Thus perifollicular, lymphohistiocytic inflammation was moderate to severe in 83% of cases and mild to absent in 17%; perifollicular fibrosis was moderate to severe in 97% of cases and mild in 3%. Fibrosed follicular units averaged 4 per patient. Findings reflecting acute or sub acute phases included hydropic degeneration of follicular epithelium in 13%, lichenoid dermatitis in 6% and colloid bodies in 4% of patients. This series underlines the increasing incidence of FFA and confirms its relationship to lichen planopilaris. A goal here is to find out why this apparently new disease has evolved and spread. Presumably, it is an autoimmune process. Are genetic and even infective factors involved?
Cicatricial alopecia - Update
Ralph M. Trüeb
Center for Dermatology and Hair Diseases, Wallisellen-Zurich, Switzerland.
Cicatricial alopecias encompass a diverse group of disorders characterized by irreversible hair loss due to destruction of the hair follicle. Where there is no obvious physical/chemical injury or infectious etiology, clinical differential diagnosis may be difficult. On the basis of histologic findings, a differentiation is made between primary and secondary scarring alopecia due to preferential destruction of the follicle, or resulting from events outside impinging upon and eradicating the follicle, respectively. The former includes well-defined chronic-inflammatory diseases further differentiated depending on the type and pattern of inflammation. Although clinicopathologic features allow for diagnosis in many cases, diagnostic certainty is sometimes elusive, and therapeutic limits reflect the boundaries of our present understanding. With expanding technologies for dissecting the immunologic and molecular basis, there is hope for a deeper understanding of the underlying pathogenesis and novel therapeutic interventions. Among these, currently, microarray analysis is used to identify disease associated gene expression patterns. For instance, microarray analysis of lichen planopilaris (LPP), compared to normal scalp biopsies, identified decreased expression of the peroxisome proliferator-activated receptor (PPAR) gamma, and it has been proposed that PPARgamma-targeted therapy may represent a new treatment strategy for LPP. Finally, the gene expression profiles in LPP and pseudopelade Brocq (PPB) were found to be sufficiently distinguishable to suggest that LPP and PPB should be regarded as biologically distinct entities. It remains to hope that further studies on these lines will also help to clarify the nosologic classification of controversial entities such as the follicular degeneration syndrome, fibrosing alopecia in a pattern distribution, and central centrifugal cicatricial alopecia.
Trichoscopy in scarring alopecia
Adriana Rakowska 1 *, Elzbieta Kowalska-Oledzka 1 , Monika Slowinska 1 , Malgorzata Olszewska 2 , Lidia Rudnicka 1
1 Department of Dermatology, Central Medical Hospital MSWiA, Warsaw, Poland, 2 Department of Dermatology, Warsaw Medical University, Warsaw, Poland.
Trichoscopy is widely used in differential diagnosis of non-scarring alopecia. The purpose of the study was establishing usefulness of trichoscopy in diagnosing diverse types of scarring alopecia. Trichoscopy was performed in 1223 patients with hair loss, including 43 patients with scarring alopecia. Trichoscopy revealed: in discoid lupus erythematosus (N=13): dark-brown discoloration on the skin, big brown-yellow dots and thick and twisted vascular loops; in lichen planopilaris (N=19): milky-red areas with elongated vessels, oriented perpendicularly along follicular units; in folliculitis decalvans (N=6): tufted hairs and marked grey and white perifollicular hyperkeratosis with the starburst pattern; in perifolliculitis capitis abscedens et suffodiens (N=5): yellow and red areas and yellow dots of "three-dimensional" structure. These features were not found in patients with non-scarring alopecia. The results of our study indicate that trichoscopy allows quick and non-invasive differential diagnosis in different types of scarring alopecia.
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