Kůže je důležitý bariérový orgán. Její anatomická a funkční zralost je jedním z limitů přežití novorozence a její stav značně ovlivňuje fyzickou a psychickou kvalitu života po celý život člověka. Četná onemocnění kůže vznikají na genetickém podkladě. Znalost vývojových mechanismů a souvislostí je proto důležitá i v běžné dermatologické praxi. Dermatolog navíc může tuto znalost využít při hledání souvislostí kožních a mimokožních projevů, a může tak sehrát důležitou roli v časné diagnostice některých vrozených onemocnění.
Skin is an important barrier organ. Anatomically and functionally mature skin is not only limiting for survival of a newborn, but skin integrity influences significantly physical as well as psychical quality of life in humans. Many skin diseases are determined genetically. Therefore, the knowledge of skin development mechanisms and its connections is important in medical practice and can be used by dermatologists while correcting cutaneous and non-cutaneous manifestations, which can play a major role in the early diagnostics of inherited diseases.
- MeSH
- chromozomální aberace MeSH
- dědičnost MeSH
- epigenomika MeSH
- genom lidský * genetika MeSH
- kožní abnormality MeSH
- kožní nemoci genetika MeSH
- kůže * embryologie MeSH
- lidé MeSH
- mutace genetika MeSH
- nehty růst a vývoj MeSH
- vlasy, chlupy růst a vývoj MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Two theories address the origin of repeating patterns, such as hair follicles, limb digits, and intestinal villi, during development. The Turing reaction-diffusion system posits that interacting diffusible signals produced by static cells first define a prepattern that then induces cell rearrangements to produce an anatomical structure. The second theory, that of mesenchymal self-organisation, proposes that mobile cells can form periodic patterns of cell aggregates directly, without reference to any prepattern. Early hair follicle development is characterised by the rapid appearance of periodic arrangements of altered gene expression in the epidermis and prominent clustering of the adjacent dermal mesenchymal cells. We assess the contributions and interplay between reaction-diffusion and mesenchymal self-organisation processes in hair follicle patterning, identifying a network of fibroblast growth factor (FGF), wingless-related integration site (WNT), and bone morphogenetic protein (BMP) signalling interactions capable of spontaneously producing a periodic pattern. Using time-lapse imaging, we find that mesenchymal cell condensation at hair follicles is locally directed by an epidermal prepattern. However, imposing this prepattern's condition of high FGF and low BMP activity across the entire skin reveals a latent dermal capacity to undergo spatially patterned self-organisation in the absence of epithelial direction. This mesenchymal self-organisation relies on restricted transforming growth factor (TGF) β signalling, which serves to drive chemotactic mesenchymal patterning when reaction-diffusion patterning is suppressed, but, in normal conditions, facilitates cell movement to locally prepatterned sources of FGF. This work illustrates a hierarchy of periodic patterning modes operating in organogenesis.
- MeSH
- buněčná diferenciace MeSH
- inbrední kmeny myší MeSH
- kůže cytologie embryologie metabolismus MeSH
- myši MeSH
- rozvržení tělního plánu MeSH
- signální transdukce MeSH
- stanovení celkové genové exprese MeSH
- transformující růstový faktor beta metabolismus fyziologie MeSH
- vlasový folikul embryologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Hair follicles are unique organs undergoing regular cycles of proliferation, differentiation, and apoptosis. The final step of apoptosis is, in general, mediated by executioner caspases comprising caspase-3, -6 and -7. Despite their commonly accepted apoptotic function, executioner caspases also participate in non-apoptotic processes. In the present study, we investigated activation (cleavage) of caspase-7 in mouse hair follicles and surrounding tissue during embryonic development into adulthood. Casp7 (-/-) mice were examined to understand the effect of caspase-7 deficiency in the skin. The activated form of caspase-7 was observed during embryonic hair follicle development, as well as in the first hair cycle. In general, activation of caspase-7 did not correlate with apoptosis and activation of caspase-3, except during physiological hair follicle regression. Notably, cleaved caspase-7 was observed in mast cells and its deficiency in the adult skin resulted in increased mast cell number. Our study shows for the first time activated caspase-7 in hair follicles and mast cells and indicates its non-apoptotic roles in the skin.
- MeSH
- aktivace enzymů MeSH
- apoptóza * MeSH
- exprese genu MeSH
- kaspasa 3 metabolismus MeSH
- kaspasa 7 nedostatek genetika metabolismus MeSH
- kaspasy genetika metabolismus MeSH
- kůže embryologie metabolismus MeSH
- mastocyty metabolismus MeSH
- myši knockoutované MeSH
- myši MeSH
- počet buněk MeSH
- transport proteinů MeSH
- vlasový folikul embryologie metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Aims. The human fetal period of life is when there is complete development of the dermatoglyphic pattern. However, to date not enough is known about the differentiation of the papillary terrain during prenatal life and which mechanisms are involved in this differentiation. The aims of the present study are to contribute to the clarification of the embryogenesis of the papillary ridges and to compare their development on the hands and feet. Methods. The hands and feet of 35 human embryos and fetuses were examined in the present study. We used a new and original method of orientation. The right hand with right foot or left hand with left foot of each embryo/fetus were placed together into one paraffin block. Three different planes of orientation were used. Results. Volar pad development and papillary ridge formation are identical on hands and feet, but the developmental stages on feet lag one week behind those of hands. Papillary ridge embryogenesis follows the cranio-caudal developmental direction. After developmental week 14 the configuration of the future dermatoglyphic pattern has already ocurred at the dermo-epidermal junction. We consider the 6th month of prenatal development to be the gestational age when the papillary ridge development is completed. Conclusion. Our observations lead to the conclusion that the increased vascularization of dermis considerably affects papillary ridge formation.
- MeSH
- dermatoglyfika MeSH
- kůže embryologie MeSH
- lidé MeSH
- noha (od hlezna dolů) embryologie MeSH
- plod MeSH
- ruka embryologie MeSH
- Check Tag
- lidé MeSH
310 s. : il. ; 25 cm
- MeSH
- dermatologie MeSH
- fyziologie kůže MeSH
- kožní nemoci diagnóza etiologie genetika klasifikace patologie prevence a kontrola terapie virologie MeSH
- kůže anatomie a histologie cytologie embryologie imunologie mikrobiologie patofyziologie patologie virologie MeSH
- Publikační typ
- monografie MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- dermatovenerologie
