Caspases have functions particularly in apoptosis and inflammation. Increasing evidence indicates novel roles of these proteases in cell differentiation, including those involved in osteogenesis. This investigation provides a complex screening of osteogenic markers affected by pan caspase inhibition in micromass cultures derived from mouse forelimbs. PCR Array analysis showed significant alterations in expression of 49 osteogenic genes after 7 days of inhibition. The largest change was a decrease in CD36 expression, which was confirmed at organ level by caspase inhibition in cultured mouse ulnae followed by CD36 immunohistochemical analysis. So far, available data point to osteogenic potential of pro-apoptotic caspases. Therefore, the expression of pro-apoptotic caspases (-3, -6, -7, -8, -9) within the growth plate of mouse forelimbs at the stage where the individual zones are clearly apparent was studied. Caspase-9 was reported in the growth plate for the first time as well as caspase-6 and -7 in the resting zone, caspase-7 in the proliferation, and caspase-6 and -8 in the ossification zone. For all caspases, there was a gradient increase in activation toward the ossification zone. The distribution of staining varied significantly from that of apoptotic cells, and thus, the results further support non-apoptotic participation of caspases in osteogenesis.

• Klíčová slova
• PCR Array analysis, caspases, endochondral ossification, growth plate, immunohistochemistry, micromass cultures,
• MeSH
• antigeny CD36 analýza   genetika   MeSH
• imunohistochemie MeSH
• inhibitory kaspas farmakologie   MeSH
• kaspasy metabolismus   MeSH
• kultivované buňky MeSH
• myši MeSH
• orgánové kultury - kultivační techniky MeSH
• osteogeneze * účinky léků   MeSH
• přední končetina růst a vývoj   metabolismus   MeSH
• vývojová regulace genové exprese účinky léků   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny CD36 MeSH
• inhibitory kaspas MeSH
• kaspasy MeSH

Caspase-9 is the major apical caspase responsible for triggering the intrinsic apoptotic pathway. Our previous study indicated that specific inhibition of caspase-9 caused microscopically evident alterations in appearance of the primary chondrogenic cultures which cannot be explained by decrease in apoptosis. To describe a complex molecular background of this effect, proteomics analysis of control and caspase-9 inhibitor-treated chondrogenic cultures were performed. Proteins were extracted, identified and quantified using LC-MS in both data dependent and data independent acquisition (DIA) mode. While directDIA analysis of diaPASEF data obtained using timsTOF Pro LC-MS system revealed 7849 protein groups (Q-value <0.01), a parallel analysis of iTRAQ-2DLC-MS3 and conventional DIA-MS data identified only 5146 and 4098 protein groups, respectively, showing diaPASEF a superior method for the study. The detailed analysis of diaPASEF data disclosed 236/551 significantly down-/up-regulated protein groups after caspase-9 inhibition, respectively (|log2FC|>0.58, Q value <0.05). Classification of downregulated proteins revealed changes in extracellular matrix organization, collagen metabolism, and muscle system processes. Moreover, deregulations suggest a switch from glycolytic to lipid based metabolism in the inhibited cells. No essential changes were found in the proteins involved in apoptosis. The data indicate new non-apoptotic participation of caspases in chondrocyte homeostasis with potential applications in cartilage pathophysiology.

• Klíčová slova
• caspase-9, chondrogenesis, diaPASEF, micromass cultures, proteomics,
• MeSH
• apoptóza * MeSH
• chondrocyty * metabolismus   MeSH
• kaspasa 9 metabolismus   farmakologie   MeSH
• kaspasy metabolismus   farmakologie   MeSH
• signální transdukce MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kaspasa 9 MeSH
• kaspasy MeSH

The Myb locus encodes the c-Myb transcription factor involved in controlling a broad variety of cellular processes. Recently, it has been shown that c-Myb may play a specific role in hard tissue formation; however, all of these results were gathered from an analysis of intramembranous ossification. To investigate a possible role of c-Myb in endochondral ossification, we carried out our study on the long bones of mouse limbs during embryonic development. Firstly, the c-myb expression pattern was analyzed by in situ hybridization during endochondral ossification of long bones. c-myb positive areas were found in proliferating as well as hypertrophic zones of the growth plate. At early embryonic stages, localized expression was also observed in the perichondrium and interdigital areas. The c-Myb protein was found in proliferating chondrocytes and in the perichondrium of the forelimb bones (E14.5-E17.5). Furthermore, protein was detected in pre-hypertrophic as well as hypertrophic chondrocytes. Gain-of-function and loss-of-function approaches were used to test the effect of altered c-myb expression on chondrogenesis in micromass cultures established from forelimb buds of mouse embryos. A loss-of-function approach using c-myb specific siRNA decreased nodule formation, as well as downregulated the level of Sox9 expression, a major marker of chondrogenesis. Transient c-myb overexpression markedly increased the formation of cartilage nodules and the production of extracellular matrix as detected by intense staining with Alcian blue. Moreover, the expression of early chondrogenic genes such as Sox9, Col2a1 and activity of a Col2-LUC reporter were increased in the cells overexpressing c-myb while late chondrogenic markers such as Col10a1 and Mmp13 were not significantly changed or were downregulated. Taken together, the results of this study demonstrate that the c-Myb transcription factor is involved in the regulation and promotion of endochondral bone formation.

• Klíčová slova
• Chondrogenesis, Endochondral bone, Micromass cultures, Mouse limbs, Up- and down-regulation, siRNA,
• MeSH
• biologické markery metabolismus   MeSH
• buněčná diferenciace MeSH
• chondrogeneze fyziologie   MeSH
• hybridizace in situ MeSH
• končetiny embryologie   MeSH
• myši MeSH
• protoonkogenní proteiny c-myb genetika   fyziologie   MeSH
• umlčování genů MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biologické markery MeSH
• protoonkogenní proteiny c-myb MeSH

The transcription factor c-MYB is a well-known marker of undifferentiated cells such as haematopoietic cell precursors, but recently it has also been observed in differentiated cells that produce hard tissues. Our previous findings showed the presence of c-MYB in intramembranous bones and its involvement in the chondrogenic steps of endochondral ossification, where the up-regulation of early chondrogenic markers after c-myb overexpression was observed. Since we previously detected c-MYB in osteoblasts, we aimed to analyse the localisation of c-MYB during later stages of endochondral bone formation and address its function during bone matrix production. c-MYB-positive cells were found in the chondro-osseous junction zone in osteoblasts of trabecular bone as well as deeper in the zone of ossification in cells of spongy bone. To experimentally evaluate the osteogenic potential of c-MYB during endochondral bone formation, micromasses derived from embryonic mouse limb buds were established. Nuclear c-MYB protein expression was observed in long-term micromasses, especially in the areas around nodules. c-myb overexpression induced the expression of osteogenic-related genes such as Bmp2, Comp, Csf2 and Itgb1. Moreover, alizarin red staining and osteocalcin labelling promoted mineralised matrix production in c-myb-overexpressing cultures, whereas downregulation of c-myb by siRNA reduced mineralised matrix production. In conclusion, c-Myb plays a role in the osteogenesis of long bones by inducing osteogenic genes and causing the enhancement of mineral matrix production. This action of the transcription factor c-Myb might be of interest in the future for the establishment of novel approaches to tissue regeneration.

• Klíčová slova
• Micromass cultures, Mineralised matrix, Mouse limbs, Osteogenesis, PCR Array,
• MeSH
• buněčná diferenciace fyziologie   MeSH
• chondrogeneze fyziologie   MeSH
• kosti a kostní tkáň metabolismus   MeSH
• myši MeSH
• osteoblasty cytologie   metabolismus   MeSH
• osteogeneze fyziologie   MeSH
• osteokalcin metabolismus   MeSH
• protoonkogenní proteiny c-myb genetika   metabolismus   MeSH
• upregulace MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• osteokalcin MeSH
• protoonkogenní proteiny c-myb MeSH

We isolated and expanded stem cells from dental pulp from extracted third molars using an innovative culture method consisting of low serum-containing medium supplemented with epidermal growth factor and platelet-derived growth factor BB. We evaluated the differentiation potential of these cells when they were growing either adherently or as micromass/spheroid cultures in various media. Undifferentiated and differentiated cells were analyzed by flow cytometry, immunocytochemistry and immunoblotting. The flow cytometry results showed that the dental pulp stem cells (DPSCs) were positive for mesenchymal stromal cell markers, but negative for hematopoietic markers. Immunocytochemical and/or immunoblotting analyses revealed the expression of numerous stem cell markers, including nanog, Sox2, nestin, Musashi-1 and nucleostemin, whereas they were negative for markers associated with differentiated neural, vascular and hepatic cells. Surprisingly, the cells were only slightly positive for α-smooth muscle actin, and a heterogeneous expression of CD146 was observed. When cultured in osteogenic media, they expressed osteonectin, osteopontin and procollagen I, and in micromass cultures, they produced collagen I. DPSCs cultured in TGF-β1/3-supplemented media produced extracellular matrix typical of cartilaginous tissue. The addition of vascular endothelial growth factor to serum-free media resulted in the expression of endothelial markers. Interestingly, when cultured in neurogenic media, DPSCs exhibited de novo or upregulated markers of undifferentiated and differentiated neural cells. Collectively, our data show that DPSCs are self-renewing and able to express markers of bone, cartilage, vascular and neural tissues, suggesting their multipotential capacity. Their easy accessibility makes these cells a suitable source of somatic stem cells for tissue engineering.

• MeSH
• aktiny metabolismus   MeSH
• antigen CD146 metabolismus   MeSH
• buněčná diferenciace účinky léků   MeSH
• buněčný rodokmen účinky léků   MeSH
• chondrogeneze účinky léků   MeSH
• endoteliální buňky cytologie   účinky léků   metabolismus   MeSH
• imunohistochemie MeSH
• kmenové buňky účinky léků   patologie   MeSH
• kultivační média bez séra farmakologie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• molár třetí patologie   MeSH
• myocyty hladké svaloviny cytologie   účinky léků   metabolismus   MeSH
• myofibroblasty cytologie   účinky léků   metabolismus   MeSH
• neurony cytologie   účinky léků   metabolismus   MeSH
• osteogeneze účinky léků   MeSH
• průtoková cytometrie MeSH
• zaklíněný zub patologie   MeSH
• zubní dřeň patologie   MeSH
• Check Tag
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aktiny MeSH
• antigen CD146 MeSH
• kultivační média bez séra MeSH

Caspases are key enzymatic components of the intracellular apoptotic machinery, and their role in mammalian systems is often studied using fluoromethylketone (FMK) inhibitors. Despite many advantages of such approach, efficiency of the inhibitor and membrane permeability speed are often questioned. This work therefore focuses on an exact evaluation of caspase-3 FMK inhibition dynamics in camptothecin-induced mesenchymal micromasses. Two parameters of caspase-3 FMK inhibitor were investigated: first, the stability of the inhibitory potential in the time course of cultivation and, simultaneously, the dynamics of caspase-3 FMK inhibition after camptothecin-induced apoptosis peak. A photon-counting chemiluminescence approach was applied for quantification of active caspase-3. The sensitivity of the photon-counting method allowed for evaluation of active caspase-3 concentration in femtogram amounts per cell. The inhibitor penetrated the cells within the first minute after its application, and the peak of caspase-3 started to decline to the blank level after 30 min. The inhibitory effect of the FMK inhibitor was unchanged during the entire 48 h of cultivation.

• MeSH
• apoptóza účinky léků   MeSH
• inbrední kmeny myší MeSH
• inhibitory kaspas farmakologie   MeSH
• kamptothecin farmakologie   MeSH
• kaspasa 3 metabolismus   fyziologie   MeSH
• kultivované buňky MeSH
• luminiscenční měření metody   MeSH
• myši MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• inhibitory kaspas MeSH
• kamptothecin MeSH
• kaspasa 3 MeSH

Tyrosine kinase inhibitors are being developed for therapy of malignancies caused by oncogenic FGFR signaling but little is known about their effect in congenital chondrodysplasias or craniosynostoses that associate with activating FGFR mutations. Here, we investigated the effects of novel FGFR inhibitor, ARQ 087, in experimental models of aberrant FGFR3 signaling in cartilage. In cultured chondrocytes, ARQ 087 efficiently rescued all major effects of pathological FGFR3 activation, i.e. inhibition of chondrocyte proliferation, loss of extracellular matrix and induction of premature senescence. In ex vivo tibia organ cultures, ARQ 087 restored normal growth plate architecture and eliminated the suppressing FGFR3 effect on chondrocyte hypertrophic differentiation, suggesting that it targets the FGFR3 pathway specifically, i.e. without interference with other pro-growth pathways. Moreover, ARQ 087 inhibited activity of FGFR1 and FGFR2 mutants associated with Pfeiffer, Apert and Beare-Stevenson craniosynostoses, and rescued FGFR-driven excessive osteogenic differentiation in mouse mesenchymal micromass cultures or in ex vivo calvarial organ cultures. Our data warrant further development of ARQ 087 for clinical use in skeletal disorders caused by activating FGFR mutations.

• Klíčová slova
• ARQ 087, Achondroplasia, Craniosynostosis, FGFR, Fibroblast growth factor receptor, Inhibitor, Skeletal dysplasia,
• MeSH
• aniliny farmakologie   terapeutické užití   MeSH
• bezbuněčný systém MeSH
• buněčná diferenciace * účinky léků   MeSH
• buněčné kultury MeSH
• chinazoliny farmakologie   terapeutické užití   MeSH
• chondrocyty účinky léků   metabolismus   patologie   MeSH
• extracelulární matrix účinky léků   metabolismus   MeSH
• fibroblastový růstový faktor 2 farmakologie   MeSH
• končetinové pupeny patologie   MeSH
• kraniosynostózy farmakoterapie   genetika   patologie   MeSH
• krysa rodu Rattus MeSH
• kur domácí MeSH
• lebka patologie   MeSH
• mutace genetika   MeSH
• myši MeSH
• orgánové kultury - kultivační techniky MeSH
• proliferace buněk účinky léků   MeSH
• receptory fibroblastových růstových faktorů genetika   MeSH
• signální transdukce * MeSH
• stárnutí buněk účinky léků   MeSH
• tibie účinky léků   patologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aniliny MeSH
• chinazoliny MeSH
• derazantinib MeSH Prohlížeč
• fibroblastový růstový faktor 2 MeSH
• receptory fibroblastových růstových faktorů MeSH

Aberrant fibroblast growth factor (FGF) signaling disturbs chondrocyte differentiation in skeletal dysplasia, but the mechanisms underlying this process remain unclear. Recently, FGF was found to activate canonical WNT/β-catenin pathway in chondrocytes via Erk MAP kinase-mediated phosphorylation of WNT co-receptor Lrp6. Here, we explore the cellular consequences of such a signaling interaction. WNT enhanced the FGF-mediated suppression of chondrocyte differentiation in mouse limb bud micromass and limb organ cultures, leading to inhibition of cartilage nodule formation in micromass cultures, and suppression of growth in cultured limbs. Simultaneous activation of the FGF and WNT/β-catenin pathways resulted in loss of chondrocyte extracellular matrix, expression of genes typical for mineralized tissues and alteration of cellular shape. WNT enhanced the FGF-mediated downregulation of chondrocyte proteoglycan and collagen extracellular matrix via inhibition of matrix synthesis and induction of proteinases involved in matrix degradation. Expression of genes regulating RhoA GTPase pathway was induced by FGF in cooperation with WNT, and inhibition of the RhoA signaling rescued the FGF/WNT-mediated changes in chondrocyte cellular shape. Our results suggest that aberrant FGF signaling cooperates with WNT/β-catenin in suppression of chondrocyte differentiation.

• Klíčová slova
• Cartilage, Chondrocyte, Differentiation, FGFR3, Fibroblast growth factor receptor, WNT,
• MeSH
• beta-katenin genetika   metabolismus   MeSH
• biologické modely MeSH
• buněčná diferenciace účinky léků   genetika   MeSH
• chondrocyty účinky léků   metabolismus   MeSH
• chrupavka cytologie   účinky léků   metabolismus   MeSH
• fibroblastové růstové faktory farmakologie   MeSH
• fibroblastový růstový faktor 2 farmakologie   MeSH
• HEK293 buňky MeSH
• končetinové pupeny účinky léků   embryologie   metabolismus   MeSH
• konfokální mikroskopie MeSH
• krysa rodu Rattus MeSH
• kultivované buňky MeSH
• LDL receptor related protein 6 genetika   metabolismus   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• protein Wnt3A farmakologie   MeSH
• proteiny Wnt genetika   metabolismus   farmakologie   MeSH
• receptory fibroblastových růstových faktorů genetika   metabolismus   MeSH
• signální transdukce účinky léků   genetika   MeSH
• synergismus léků MeSH
• transkriptom účinky léků   genetika   MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• beta-katenin MeSH
• fibroblastové růstové faktory MeSH
• fibroblastový růstový faktor 2 MeSH
• LDL receptor related protein 6 MeSH
• Lrp6 protein, mouse MeSH Prohlížeč
• protein Wnt3A MeSH
• proteiny Wnt MeSH
• receptory fibroblastových růstových faktorů MeSH

Caspase-12 is a molecule whose functions are still not well understood. Although its expression has been found in various tissues, specific roles have been described in only a few cases. These include the effect of caspase-12 on murine bone cell differentiation during craniofacial development. This work focused on the development of the limbs taking place through endochondral ossification, which precedes the formation of the cartilaginous growth plate. Caspase-12 was described here for the first time in growth plate chondrocytes during physiological development. Using pharmacological inhibition, caspase-12 was found to affect chondrogenesis. Limb-derived micromass cultures showed a significantly increased area of chondrogenic nodules after caspase-12 inhibition and there were changes in gene expression, the most significant of which was the reduction of Mmp9. These data point to potential new functions of caspase-12 in chondrogenesis.

• Klíčová slova
• Caspase-12, Chondrocyte, Chondrogenesis, Differentiation, Growth plate,
• MeSH
• buněčná diferenciace MeSH
• chondrocyty * MeSH
• chondrogeneze * fyziologie   MeSH
• inhibitory kaspas farmakologie   MeSH
• kaspasa 12 * metabolismus   genetika   MeSH
• kultivované buňky MeSH
• matrixová metaloproteinasa 9 metabolismus   genetika   MeSH
• myši MeSH
• růstová ploténka růst a vývoj   MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• inhibitory kaspas MeSH
• kaspasa 12 * MeSH
• matrixová metaloproteinasa 9 MeSH

Besides cell death, caspase-9 participates in non-apoptotic events, including cell differentiation. To evaluate a possible impact on the expression of chondrogenic/osteogenic factors, a caspase-9 inhibitor was tested in vitro. For this purpose, mouse forelimb-derived micromass cultures, the most common chondrogenic in vitro model, were used. The following analyses were performed based on polymerase chain reaction (PCR) arrays and real-time PCR. The expression of several chondrogenesis-related genes was shown to be altered, some of which may impact chondrogenic differentiation (Bmp4, Bmp7, Sp7, Gli1), mineral deposition (Alp, Itgam) or the remodelling of the extracellular matrix (Col1a2, Mmp9) related to endochondral ossification. From the cluster of genes with altered expression, Mmp9 showed the most significant decrease in expression, of more than 50-fold. Additionally, we determined the possible impact of caspase-9 downregulation on the expression of other Mmp genes. A mild increase in Mmp14 was observed, but there was no change in the expression of other studied Mmp genes (-2, -3, -8, -10, -12, -13). Interestingly, inhibition of Mmp9 in micromasses led to decreased expression of some chondrogenic markers related to caspase-9. These samples also showed a decreased expression of caspase-9 itself, suggesting a bidirectional regulation of these two enzymes. These results indicate a specific impact of caspase-9 inhibition on the expression of Mmp9. The localisation of these two enzymes overlaps in resting, proliferative and pre-hypertrophic chondrocytes during in vivo development, which supports their multiple functions, either apoptotic or non-apoptotic. Notably, a coincidental expression pattern was identified in Pik3cg, a possible candidate for Mmp9 regulation.

• Klíčová slova
• Caspase-9, Chondrogenic differentiation, Micromasses, Mmp-9, Non-apoptotic functions,
• MeSH
• buněčná diferenciace MeSH
• chondrocyty * MeSH
• chondrogeneze * fyziologie   MeSH
• inhibitory kaspas metabolismus   farmakologie   MeSH
• kaspasa 9 genetika   metabolismus   MeSH
• kultivované buňky MeSH
• myši MeSH
• osteogeneze MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• inhibitory kaspas MeSH
• kaspasa 9 MeSH