The mouse incisor is a frequently used model in studies of the molecular control of organ development. The appropriate interpretation of data on normogenesis is essential for understanding the data obtained in mutant mice. For this reason, we performed a very detailed investigation of the development of the upper incisor in wild-type mice from embryonic day (ED) 11.5 till 14.5. A combination of histology, whole mount in situ hybridization, computer-aided three-dimensional reconstructions, and fluorescent microscopy, has been used. Several sonic hedgehog (Shh) expression domains have been detected in the upper incisor region during early prenatal development. At ED11.5-13.5, there was a single Shh positive domain present in the anterior part of left or right upper jaw arches, corresponding to the epithelial thickening. More posteriorly, a new Shh expression domain appeared in the incisor bud in the developmentally more advanced ED13.5 embryos. At ED14.5, only this posterior Shh expression in the incisor germ remained detectable. This study brings new insights into the early development of the upper incisor in mice and completes the data on normal mouse incisor development. The temporal-spatial pattern of Shh expression reflects the development of two tooth generations, being detectable in two successive, antero-posteriorly located areas in the prospective incisor region in the upper jaw. The first, anterior and superficial Shh expression domain reflects the rudimentary tooth development suppressed during evolution. Only the subsequent, posterior and deeper Shh expression region, appearing at ED13.5, correlates with the prospective upper functional incisor in wild-type mice.

• MeSH
• fluorescenční mikroskopie MeSH
• fylogeneze MeSH
• hybridizace in situ MeSH
• maxila embryologie   metabolismus   MeSH
• myši transgenní MeSH
• myši MeSH
• odontogeneze MeSH
• proteiny hedgehog genetika   metabolismus   MeSH
• řezáky embryologie   metabolismus   MeSH
• vývojová regulace genové exprese * MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

For teeth as for any organ, knowledge of normal development is essential for the proper interpretation of developmental anomalies in mutant mice. It is generally accepted that tooth formation is initiated with a single signaling center that, in the incisor region, is exclusively related to the development of the functional adult incisor. Here, using a unique combination of computer-aided three-dimensional reconstructions and whole mount in situ hybridization of mandibles from finely staged wild-type mouse embryos, we demonstrate that several Sonic hedgehog (Shh) expression domains sequentially appear in the lower incisor region during early development. In contrast to the single Shh expression domain that is widely assumed to be present in each lower incisor area at ED12.5-13.5, we identified two spatially distinct regions of Shh expression that appear in an anterior-posterior sequence during this period. The initial anterior, more superficially located Shh expression region represented the rudimentary (so-called deciduous) incisor, whereas only the later posterior deeper situated region corresponded to the prospective functional incisor. In the more advanced embryos, only this posterior Shh expression in the incisor bud was detectable as a precursor of the enamel knot. This study offers a new interpretation of published molecular data on the mouse incisor from initiation through ED13.5. We suggest that, as with Shh expression, other molecular data that have been ascribed to the progressive development of the mouse functional incisor at early stages, in fact, correspond to a rudimentary incisor whose development is aborted.

• MeSH
• čelisti embryologie   metabolismus   MeSH
• embryonální vývoj MeSH
• epitel metabolismus   MeSH
• myši transgenní MeSH
• myši MeSH
• proteiny hedgehog genetika   metabolismus   MeSH
• řezáky embryologie   metabolismus   MeSH
• trans-aktivátory genetika   metabolismus   MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Východiska: Meduloblastom (MB) je nejčastější maligní nádor centrálního nervového systému u dětí. V ČR ročně onemocní tímto nádorem přibližně 10–12 dětí. MB jsou považovány za vysoce rizikové nádory se sklonem k metastazování. Současné pokroky v molekulární diagnostice pomáhají ve zpřesnění diagnózy a předpovědi klinického průběhu onemocnění. V současné době jsou MB rozdělovány do podskupin, a to na základě molekulárních drah řídících jejich vznik, na WNT aktivované, SHH aktivované, skupinu 3 a 4. Jednotlivé podskupiny se liší svou histologií, klinickým průběhem, genomickými změnami a profily genové exprese. Cílem naší studie je klasifikace pacientů s MB do čtyř základních molekulárních skupin a porovnání získaných výsledků s literaturou. Materiál a metody: U pacientů s MB je v rámci naší studie prováděno profilování genových expresí pomocí Affymetrix GeneChip Human Gene 1.0. ST Array (Thermo Fisher Scientific, MA, USA). Vstupním materiálem je celková RNA izolovaná ze zamražené nádorové tkáně. Samotná klasifikace je založena na metodě vyvinuté P. Northcottem v roce 2011. Výsledky: Od dubna 2015 do února 2019 bylo do naší studie zařazeno celkem 21 pacientů s MB. Medián věku pacienta v době diagnózy byl 6 let, zařazeno bylo 14 chlapců a 7 dívek. U pacientů bylo provedeno profilování genové exprese a následná molekulární klasifikace MB. Zjistili jsme, že nejčastěji zastoupená skupina MB byla skupina 4 (9 pacientů, 43 %), následovala skupina 3 (5 pacientů, 24 %), SHH aktivovaný MB (4 pacienti, 19 %) a nejméně zastoupenou skupinou byl WNT aktivovaný MB (3 pacienti, 14 %). Výsledky stanovení podskupiny MB byly úspěšně korelovány s histopatologickým nálezem a dalšími molekulárně genetickými vyšetřeními. Závěr: Molekulární klasifikace pacientů s MB, která byla zavedena na našem pracovišti, umožňuje lépe porozumět tomuto heterogennímu charakteru onemocnění a pomáhá v terapeutickém plánování.

Background: Medulloblastoma (MB) is the most common malignant tumour of the central nervous system in children. MB is considered to be high risk tumour propensity to metastasize. In the Czech Republic, approximately 10-12 children are affected annually by this tumour. Recent progress in molecular diagnostics helps to refine the diagnosis and estimate clinical prognosis of the disease. Currently, MBs are subclassified into WNT-activated, SHH-activated, group 3, and 4 based on molecular pathways that drive their tumorigenesis. Each subtype differs in its histopathology, clinical features, genomic changes and gene expressions. The aim of our study is to classify patient‘s MBs into four basic molecular groups and compare our results with published data. Material and methods: In our study we analysed expression profiles using Affymetrix GeneChip Human Gene 1.0. ST Array (Thermo Fisher Scientific, MA, USA). As input material RNA extracted from the fresh frozen tissue was used. Molecular classification based on the method established by P. Northcott in 2011 was performed. Results: From April 2015 to February 2019, 21 patients with MBs were included in our study. Median age of the patients at the time of diagnosis was 6 years, 14 boys and 7 girls were enrolled. Gene expression profiling and molecular classification of MBs was performed. Based on this methodology, we found the most frequently represented subgroup of MB was group 4 (9 patients, 43%), followed by group 3 (5 patients, 24%), SHH-activated MB (4 patients, 19%) and the least represented subgroup was WNT-activated MB (3 patients, 14%). Results of molecular subgroup classification of MBs were successfully correlated with histopathological findings and other molecular-genetic examinations. Conclusion: Molecular classification of MBs has been established in our institution allowing better understanding of this heterogeneous disease and helping clinicians in therapeutic planning in affected patients.

• MeSH
• dítě MeSH
• dospělí MeSH
• exprese genu MeSH
• individualizovaná medicína MeSH
• kojenec MeSH
• lidé MeSH
• meduloblastom diagnóza   genetika   MeSH
• mladiství MeSH
• předškolní dítě MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• práce podpořená grantem MeSH

Sonic hedgehog medulloblastoma encompasses a clinically and molecularly diverse group of cancers of the developing central nervous system. Here, we use unbiased sequencing of the transcriptome across a large cohort of 250 tumors to reveal differences among molecular subtypes of the disease, and demonstrate the previously unappreciated importance of non-coding RNA transcripts. We identify alterations within the cAMP dependent pathway (GNAS, PRKAR1A) which converge on GLI2 activity and show that 18% of tumors have a genetic event that directly targets the abundance and/or stability of MYCN. Furthermore, we discover an extensive network of fusions in focally amplified regions encompassing GLI2, and several loss-of-function fusions in tumor suppressor genes PTCH1, SUFU and NCOR1. Molecular convergence on a subset of genes by nucleotide variants, copy number aberrations, and gene fusions highlight the key roles of specific pathways in the pathogenesis of Sonic hedgehog medulloblastoma and open up opportunities for therapeutic intervention.

• MeSH
• dítě MeSH
• dospělí MeSH
• genetická variace MeSH
• genové regulační sítě MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• meduloblastom genetika   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nádory mozečku genetika   MeSH
• předškolní dítě MeSH
• proteiny hedgehog genetika   MeSH
• regulace genové exprese u nádorů * MeSH
• signální transdukce genetika   MeSH
• transkriptom * MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Rat hypodactyly (hd) is an autosomal recessive mutation manifesting in homozygotes as reduction or loss of digits II and III. We mapped the hd allele to a short segment of chromosome 10, containing 16 genes. None of these genes has been shown to influence limb development yet. In situ hybridization showed no changes in several important patterning genes (Shh, Fgf8, Bmp2, 4, 7). However, we found that expression of cartilage condensation marker Sox9, and Bmp receptor Bmpr1b (acting as an upstream activator of Sox9 expression) is absent from the subepithelial mesenchyme of the digit condensations II and III. The failure of the chondrogenic condensations to extend towards the subepithelial mesenchyme may reduce the size of digit primordia and underlie the subsequent loss of phalanges and reduction of metacarpals/metatarsals in hd rats.

• MeSH
• embryo savčí anatomie a histologie   metabolismus   MeSH
• fenotyp MeSH
• financování organizované MeSH
• homeodoménové proteiny genetika   metabolismus   MeSH
• končetinové pupeny abnormality   metabolismus   MeSH
• končetiny MeSH
• krysa rodu rattus MeSH
• mutace MeSH
• potkani Wistar MeSH
• receptory morfogenetických kostních proteinů typu I genetika   metabolismus   MeSH
• rozvržení tělního plánu genetika   MeSH
• transkripční faktor SOX9 genetika   metabolismus   MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH

Atypical teratoid/rhabdoid tumor (ATRT) is an aggressive central nervous system tumor characterized by loss of SMARCB1/INI1 protein expression and comprises three distinct molecular groups, ATRT-TYR, ATRT-MYC and ATRT-SHH. ATRT-SHH represents the largest molecular group and is heterogeneous with regard to age, tumor location and epigenetic profile. We, therefore, aimed to investigate if heterogeneity within ATRT-SHH might also have biological and clinical importance. Consensus clustering of DNA methylation profiles and confirmatory t-SNE analysis of 65 ATRT-SHH yielded three robust molecular subgroups, i.e., SHH-1A, SHH-1B and SHH-2. These subgroups differed by median age of onset (SHH-1A: 18 months, SHH-1B: 107 months, SHH-2: 13 months) and tumor location (SHH-1A: 88% supratentorial; SHH-1B: 85% supratentorial; SHH-2: 93% infratentorial, often extending to the pineal region). Subgroups showed comparable SMARCB1 mutational profiles, but pathogenic/likely pathogenic SMARCB1 germline variants were over-represented in SHH-2 (63%) as compared to SHH-1A (20%) and SHH-1B (0%). Protein expression of proneural marker ASCL1 (enriched in SHH-1B) and glial markers OLIG2 and GFAP (absent in SHH-2) as well as global mRNA expression patterns differed, but all subgroups were characterized by overexpression of SHH as well as Notch pathway members. In a Drosophila model, knockdown of Snr1 (the fly homologue of SMARCB1) in hedgehog activated cells not only altered hedgehog signaling, but also caused aberrant Notch signaling and formation of tumor-like structures. Finally, on survival analysis, molecular subgroup and age of onset (but not ASCL1 staining status) were independently associated with overall survival, older patients (> 3 years) harboring SHH-1B experiencing relatively favorable outcome. In conclusion, ATRT-SHH comprises three subgroups characterized by SHH and Notch pathway activation, but divergent molecular and clinical features. Our data suggest that molecular subgrouping of ATRT-SHH has prognostic relevance and might aid to stratify patients within future clinical trials.

• MeSH
• gen SMARCB1 genetika   metabolismus   MeSH
• lidé MeSH
• metylace DNA MeSH
• nádory centrálního nervového systému * genetika   MeSH
• neuroepitelové nádory * genetika   MeSH
• prognóza MeSH
• proteiny hedgehog genetika   metabolismus   MeSH
• rhabdoidní nádor * genetika   MeSH
• teratom * genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The proper positioning of organs during development is essential, yet little is known about the regulation of this process in mammals. Using murine tooth development as a model, we have found that cell migration plays a central role in positioning of the organ primordium. By combining lineage tracing, genetic cell ablation, and confocal live imaging, we identified a migratory population of Fgf8-expressing epithelial cells in the embryonic mandible. These Fgf8-expressing progenitors furnish the epithelial cells required for tooth development, and the progenitor population migrates toward a Shh-expressing region in the mandible, where the tooth placode will initiate. Inhibition of Fgf and Shh signaling disrupted the oriented migration of cells, leading to a failure of tooth development. These results demonstrate the importance of intraepithelial cell migration in proper positioning of an initiating organ.

• MeSH
• epitelové buňky cytologie   metabolismus   MeSH
• fibroblastové růstové faktory metabolismus   MeSH
• mezoderm cytologie   metabolismus   MeSH
• moláry cytologie   embryologie   metabolismus   MeSH
• morfogeneze fyziologie   MeSH
• myši MeSH
• odontogeneze fyziologie   MeSH
• pohyb buněk fyziologie   MeSH
• vývojová regulace genové exprese fyziologie   MeSH
• zuby cytologie   embryologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

The area of the oral vestibule is often a place where pathologies appear (e.g., peripheral odontomas). The origin of these pathologies is not fully understood. In the present study, we traced a cell population expressing Sonic hedgehog (Shh) from the beginning of tooth development using Cre-LoxP system in the lower jaw of wild-type (WT) mice. We focused on Shh expression in the area of the early appearing rudimentary incisor germs located anteriorly to the prospective incisors. The localization of the labelled cells in the incisor germs and also in the inner epithelial layer of the vestibular anlage showed that the first very early developmental events in the lower incisor area are common to the vestibulum oris and the prospective incisor primordia in mice. Scanning electron microscopic analysis of human historical tooth-like structures found in the vestibular area of jaws confirmed their relation to teeth and thus the capability of the vestibular tissue to form teeth. The location of labelled cells descendant of the early appearing Shh expression domain related to the rudimentary incisor anlage not only in the rudimentary and functional incisor germs but also in the externally located anlage of the oral vestibule documented the odontogenic potential of the vestibular epithelium. This potential can be awakened under pathological conditions and become a source of pathologies in the vestibular area.

• MeSH
• embryonální vývoj fyziologie   MeSH
• hybridizace in situ MeSH
• ještěři embryologie   metabolismus   MeSH
• lidé MeSH
• mikroskopie elektronová rastrovací MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• odontogeneze genetika   fyziologie   MeSH
• proteiny hedgehog genetika   metabolismus   MeSH
• řezáky embryologie   metabolismus   ultrastruktura   MeSH
• těhotenství MeSH
• ústa embryologie   metabolismus   ultrastruktura   MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Sonic hedgehog (Shh) is a morphogen involved in many developmental processes. Injection of cells (5E1) that produce a Shh-blocking antibody causes an attenuation of the Shh response, and this causes vascular malformations and impaired remodeling characterized by hemorrhages and protrusions of the anterior cardinal vein and outflow tract, delayed fusion of the dorsal aortae, impaired branching of the internal carotid artery, and delayed remodeling of the aortic arches. Distribution of smooth muscle cells in the vessel wall is unchanged. In 5E1-injected embryos, we also observed impaired assembly of endothelial cells into vascular tubes, particularly in the sixth branchial arch, around the anterior cardinal vein and around the dorsal aorta. In 5E1-treated embryos, increased numbers of macrophage-like cells, apoptotic cells, and a decreased level of proliferation were observed in head mesenchyme. Together, these observations show that Shh signaling is required at multiple stages for proper vessel formation and remodeling.

• MeSH
• branchiální krajina embryologie   metabolismus   MeSH
• cévy embryologie   metabolismus   MeSH
• financování organizované MeSH
• hybridizace in situ MeSH
• hybridomy MeSH
• imunohistochemie MeSH
• křepelky a křepelovití MeSH
• kultivované buňky MeSH
• myši MeSH
• proteiny hedgehog genetika   imunologie   metabolismus   MeSH
• protilátky imunologie   metabolismus   MeSH
• ptačí proteiny genetika   metabolismus   MeSH
• transplantace buněk MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH

BACKGROUND: In mammals, odontogenesis is regulated by transient signaling centers known as enamel knots (EKs), which drive the dental epithelium shaping. However, the developmental mechanisms contributing to formation of complex tooth shape in reptiles are not fully understood. Here, we aim to elucidate whether signaling organizers similar to EKs appear during reptilian odontogenesis and how enamel ridges are formed. RESULTS: Morphological structures resembling the mammalian EK were found during reptile odontogenesis. Similar to mammalian primary EKs, they exhibit the presence of apoptotic cells and no proliferating cells. Moreover, expression of mammalian EK-specific molecules (SHH, FGF4, and ST14) and GLI2-negative cells were found in reptilian EK-like areas. 3D analysis of the nucleus shape revealed distinct rearrangement of the cells associated with enamel groove formation. This process was associated with ultrastructural changes and lipid droplet accumulation in the cells directly above the forming ridge, accompanied by alteration of membranous molecule expression (Na/K-ATPase) and cytoskeletal rearrangement (F-actin). CONCLUSIONS: The final complex shape of reptilian teeth is orchestrated by a combination of changes in cell signaling, cell shape, and cell rearrangement. All these factors contribute to asymmetry in the inner enamel epithelium development, enamel deposition, ultimately leading to the formation of characteristic enamel ridges.

• MeSH
• aktiny metabolismus   MeSH
• lipidová tělíska metabolismus   MeSH
• odontogeneze fyziologie   MeSH
• plazi anatomie a histologie   růst a vývoj   metabolismus   MeSH
• transmisní elektronová mikroskopie MeSH
• vývojová regulace genové exprese fyziologie   MeSH
• zubní sklovina cytologie   metabolismus   ultrastruktura   MeSH
• zuby MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH