Formation Of Outgrowths Research Articles

Colleter Formation on the Leaves of Sweet Potato Microclones (Ipomoea batatas L.) under In Vitro Conditions

Microclones of in vitro vegetable sweet potato (Ipomoea batatas L.) were received and the formation of colors on their leaves was studied. The studies were carried out on three varieties of sweet potato that differ in the color of their pulp and the peel of the tubers as well as in different ripening periods: Purple, Jewel, and Muskatny. The effect of ½ norm of mineral salts MS medium, 1 norm MS and 1½ norm MS on the morphometric parameters of sweet potato microclones was studied. It was established that the use of ½ norm of mineral salts according to MS medium led to the production of rapidly growing axillary and adventitious shoots and the formation of a powerful root system in the basal part of microcuttings. The formation of secretory outgrowths was found for the first time on the leaves of sweet potato microclones when cultured under in vitro conditions. Neoplasms were referred to colleters and their characteristics were given. The dependence of the colleter formation on the microclone leaves on the cycles of culture is shown.

Atypical initial cleavage patterns minimally impact rhesus macaque in vitro embryo morphokinetics and embryo outgrowth development†.

Embryo morphokinetic analysis through time-lapse embryo imaging is envisioned as a method to improve selection of developmentally competent embryos. Morphokinetic analysis could be utilized to evaluate the effects of experimental manipulation on pre-implantation embryo development. The objectives of this study were to establish a normative morphokinetic database for in vitro fertilized rhesus macaque embryos and to assess the impact of atypical initial cleavage patterns on subsequent embryo development and formation of embryo outgrowths. The cleavage pattern and the timing of embryo developmental events were annotated retrospectively for unmanipulated in vitro fertilized rhesus macaque blastocysts produced over four breeding seasons. Approximately 50% of the blastocysts analyzed had an abnormal early cleavage event. The time to the initiation of embryo compaction and the time to completion of hatching was significantly delayed in blastocysts with an abnormal early cleavage event compared to blastocysts that had cleaved normally. Embryo hatching, attachment to an extracellular matrix, and growth during the implantation stage in vitro was not impacted by the initial cleavage pattern. These data establish normative morphokinetic parameters for in vitro fertilized rhesus macaque embryos and suggest that cleavage anomalies may not impact embryo implantation rates following embryo transfer.

O-163 The influence of aquaporin 3 on dynamics of cavitation, implantation and re-expansion after vitrification/warming

Abstract Study question We wished to investigate whether aquaporin 3 (AQP3) is involved in trophectoderm-related events: cavity formation and maintenance, implantation and re-expansion after the vitrification/warming process. Summary answer AQP3 regulates blastocoel formation and expansion. It is also required for implantation (as assessed by in vitro implantation assay) and maintaining developmental potential after vitrification. What is known already During blastocoel expansion blastocyst pulsates, i.e. contracts and re-expands in an oscillatory way. Recent studies utilizing a mouse model have shown, that the dynamics of cavitation and biomechanical properties of the trophectoderm are intertwined, and our results suggest, that it may, to a certain extent, reflect the developmental capabilities of blastocysts. Moreover, the dynamics of blastocyst re-expansion after vitrification/warming is also suggested to be a promising biomarker of embryo quality. As AQP3 is involved in water influx and transportation of small molecules (such as cryoprotectants) through the epithelial layer, it is a good candidate for a regulator of blastocoel expansion. Study design, size, duration We analyzed 142 mouse blastocysts to correlate the dynamics of their cavitation with their ability to implant in vitro (an outgrowth assay). We investigated the expression of Aqp3 throughout the preimplantation development. We tested how inhibition of AQP3 affects the dynamics of cavitation (n = 37; control n = 118) and formation of outgrowths (n = 77; control n = 81). We vitrified blastocysts with a limited activity of AQP3 (n = 41; control n = 38) and investigated their ability to re-expand and implant in vitro. Participants/materials, setting, methods The dynamics of cavitation was assessed by time-lapse imaging. After filming, mouse blastocysts were cultured for additional 4 days to test their ability to form outgrowths. Inhibition of AQP3 was performed by adding 100µM DFP00173 (a selective AQP3 inhibitor) to the culture medium. AQP3-inhibited blastocysts were analyzed for the dynamics of cavitation and outgrowth formation. Additionally, embryos with a limited activity of AQP3 were vitrified, warmed and then the outgrowth assay was performed. Main results and the role of chance Blastocysts unable to implant in vitro properly (i.e. forming too small outgrowths or not forming outgrowths at all) contract longer and more frequently than embryos that form correct outgrowths. Moreover, in such blastocysts, we observed shorter and weaker re-expansion phases. As AQP3 may be one of the regulators of cavitation, we followed its expression in embryos and showed that Aqp3 mRNA level increases from the 2-cell to the morula stage. AQP3 protein can be found in the cytoplasm during cleavage and translocates to basolateral membranes in trophectodermal cells in blastocysts. We revealed that inhibition of AQP3 resulted in delayed cavity formation. Moreover, inhibition of AQP3 significantly weakened the blastocyst’s ability to (re-)expand and also extended the duration and decreased frequency of the blastocoel contractions. Importantly, changes in the duration of contractions and amplitude of re-expansions were similar to those observed in blastocysts not able to implant in vitro properly. This accords with our observation that blastocysts with a limited activity of AQP3 are mostly unable to create outgrowths. Finally, we proved that inhibition of AQP3 strongly weakened re-expansion of the cavity after vitrification/warming. Furthermore, such blastocysts had a significantly lower ability to implant in vitro after vitrification. Limitations, reasons for caution We examined the role of AQP3 in blastocoel (re)-expansion and the relationship between cavitation dynamics and embryo’s ability to implant only in mice, so additional studies on other mammalian species, including humans, are needed. Moreover, our in vitro implantation assay does not fully reflect the complexity of implantation in vivo. Wider implications of the findings Our data indicate, that AQP3 regulates the dynamics of blastocoel expansion in mouse embryos. Impaired dynamics of cavitation, unsuccessful implantation or vitrification failures might be a result of decreased AQP3 activity, possibly not only in a mouse but also in other mammalian species, including humans. Trial registration number not applicable

Effect of Triazole Fungicides Titul Duo and Vintage on the Development of Pea (Pisum sativum L.) Symbiotic Nodules.

Triazole fungicides are widely used in agricultural production for plant protection, including pea (Pisum sativum L.). The use of fungicides can negatively affect the legume-Rhizobium symbiosis. In this study, the effects of triazole fungicides Vintage and Titul Duo on nodule formation and, in particular, on nodule morphology, were studied. Both fungicides at the highest concentration decreased the nodule number and dry weight of the roots 20 days after inoculation. Transmission electron microscopy revealed the following ultrastructural changes in nodules: modifications in the cell walls (their clearing and thinning), thickening of the infection thread walls with the formation of outgrowths, accumulation of poly-β-hydroxybutyrates in bacteroids, expansion of the peribacteroid space, and fusion of symbiosomes. Fungicides Vintage and Titul Duo negatively affect the composition of cell walls, leading to a decrease in the activity of synthesis of cellulose microfibrils and an increase in the number of matrix polysaccharides of cell walls. The results obtained coincide well with the data of transcriptomic analysis, which revealed an increase in the expression levels of genes that control cell wall modification and defense reactions. The data obtained indicate the need for further research on the effects of pesticides on the legume-Rhizobium symbiosis in order to optimize their use.

Healed speleothems: A possible indicator of seismotectonic activity in karst areas

Healed speleothems, sparsely mentioned in literature, have been noted in one of the side passages of the Demänová Cave System in Slovakia. Speleothem healing commonly proceeds in columns and flowstones after their brittle deformation. Crystallization of calcium carbonate in fractures and along their mouths results in formation of various outgrowths: subvertical ridges, subhorizontal ridges, and helictites. Morphology of the subvertical ridges and helictites indicates that they were supplied by water migrating through the fractures, while the subhorizontal ridges resulted from gravity-controlled water flow down the speleothem surface. Stable isotope composition of the outgrowths suggests that they crystallized as a result of CO2 degassing, like most speleothems. Since speleothem damages in the DCS are directly linked to fault reactivation, the healed speleothems appear to be advantageous objects for seismotectonic analysis of karst terrains.

AN IN VITRO ANGIOGENESIS MODEL BASED ON CELLULAR SPHEROIDS OBTAINED FROM CO-CULTURED ENDOTHELIOCYTES AND MESENCHYMAL STROMAL CELLS

The formation of vascular outgrowths (sprouts) from cellular spheroids based on endotheliocytes and mesenchymal stromal cells was demonstrated to take place upon culturing the spheroids in a three-dimensional fibrin gel. The results can serve as a basis for a new angiogenesis model of a high biological relevance.

Structural and Functional State of Erythrocyte Membranes at Drug Addiction

The steady growth in the number of drug addicts, especially among young people, dictates the need to find ways to prevent and treat this disease. In this regard, there is a need for a more detailed study of the mechanisms of the course of this disease using modern research methods, such as atomic force microscopy and fluorescence analysis of amino acid residues. Purpose of the work: to reveal the structural and functional state of erythrocyte membranes in drug addiction. Materials and methods. The studies were carried out on the erythrocyte membranes of 60 subjects suffering from heroin addiction. The shape and topography of the erythrocyte surface were studied, and spectral analysis of the proteins of the erythrocyte membranes was carried out. Results. The conducted AFM studies of erythrocyte membranes indicate the heterogeneity of the surface mechanical properties of the erythrocyte membranes of drug addicts. The data obtained indicate an acceleration of the aging process of erythrocytes in drug addiction, which goes in two ways: the formation of outgrowths on the plasmolemma, which subsequently die off (echinocytes) and invagination of the plasmolemma of erythrocytes (spherocytes). The fluorescence spectrum of amino acids in erythrocytes of drug addicts is characterized by a significant decrease in the intensity of almost all peaks and a shift of the fluorescence peak to the short-wave region. Findings. With drug addiction, changes in the structural integrity of red blood cells are noted. In people with drug addiction, in comparison with healthy people, there is a higher variability of the morphology of erythrocytes, which is expressed in a significant increase in the proportion of echinocytes and spherocytes against the background of a significant decrease in the number of discocytes. For the membrane proteins of erythrocytes of drug addicts, conformational changes are characteristic, manifested in a decrease in the intensity of fluorescence of aromatic amino acids, which indicates their structural modification and significant vulnerability of the hematopoietic system. They are largely determined by changes in the fluorescence intensity of tryptophan and, to a lesser extent, tyrosine, which indicates the preservation of the three-dimensional structure of the protein.

Treatment recommendations for chronic knee osteoarthritis

Primary osteoarthritis (OA) hinders an aging global population as one of the leading causes of years-lost-to-disability (YLD). OA in most patients is considered to be an overuse injury that results in degenerative inflammation of the joints with the associated formation of bony outgrowths. Due to the escalating nature of this chronic pain disease, treatment management for OA can initially begin with a more conservative approach. It can eventually lead to more invasive surgical procedures. At present, the standard of care remains initial conservative management with lifestyle changes, including weight loss with concurrent anti-inflammatory regimens. Injections are frequently used for the escalation of care, but a significant number of patients ultimately resort to total knee arthroplasty. This review will focus specifically on knee OA, providing a brief overview of risk factors and early management and in-depth exploration of the invasive interventions that can offer symptomatic relief and return of function.

Treatment of Titanium Alloys Based on Preliminary Plastic Impact

This paper proposed a new method for processing titanium alloys based on preliminary plastic impact. The reasons for the deterioration of the surface roughness of titanium alloys during machining are considered. This problem lies in the formation of outgrowths on tool cutting wedge, which leads to the cutting process taking place as in the titanium-titanium pair. The adsorption phenomenon leads to the fact that the outgrowth is saturated with gases from the environment, and a thick oxide film is formed. As a result, high temperatures arise during machining from 1100 to 1200°C, increasing the cutting forces P and friction Q, which introduce the technological system into an unstable self-oscillating process. The problem posed eliminated by the method of preliminary plastic deformation, which forms a local inhomogeneous structure. At the stage of processing the titanium billet, the cutting edge enters the region with a heterogeneous structure, destroying the chips and growth with an oxide film. Since most of the temperature, about 80% takes away with the chips, the amplitude of the self-oscillating process decreases, which reduces the surface roughness of the processed titanium alloys.

Ovarian Cancer Dissemination-A Cell Biologist's Perspective.

Epithelial ovarian cancer (EOC) comprises multiple disease states representing a variety of distinct tumors that, irrespective of tissue of origin, genetic aberrations and pathological features, share common patterns of dissemination to the peritoneal cavity. EOC peritoneal dissemination is a stepwise process that includes the formation of malignant outgrowths that detach and establish widespread peritoneal metastases through adhesion to serosal membranes. The cell biology associated with outgrowth formation, detachment, and de novo adhesion is at the nexus of diverse genetic backgrounds that characterize the disease. Development of treatment for metastatic disease will require detailed characterization of cellular processes involved in each step of EOC peritoneal dissemination. This article offers a review of the literature that relates to the current stage of knowledge about distinct steps of EOC peritoneal dissemination, with emphasis on the cell biology aspects of the process.

Differentiation of human neuroblastoma cell line IMR-32 by sildenafil and its newly discovered analogue IS00384

Sildenafil, a phosphodiesterase-5 inhibitor is FDA approved drug against erectile dysfunction. It is currently undergoing many clinical trials, alone or in combinations against different diseases. Treatment of neural progenitor cells with sildenafil is known to regulate their basal cGMP levels and enhance neurogenesis and differentiation. cGMP as well as cAMP are known to play a central role in the maintenance, repair and remodelling of the nervous system. In the present study, we report the neurodifferentiation property of sildenafil in neuroblastoma cancer cell line IMR-32. Sildenafil was found to induce the formation of neurite outgrowths that were found expressing neuronal markers, such as NeuN, NF-H and βIII tubulin. IS00384, a recently discovered PDE5 inhibitor by our laboratory, was also found to induce neurodifferentiation of IMR-32 cells. The effect of IS00384 on differentiation was even more profound than sildenafil. Both the compounds were found to elevate and activate the Guanine nucleotide exchange factor C3G, which is a regulator of differentiation in IMR-32 cells. They were also found to elevate the levels of cGMP and activate the AMPK-ACC and PI3K-Akt signalling pathways. These pathways are known to play important role in cytoskeletal rearrangements necessary for differentiation. This study highlights the role of phosphodiesterases-5 in neurodifferentiation and use of sildenafil and IS00384 as small molecule tools to study the process of cellular differentiation.

КАРБОНАТНЫЕ КОРЫ НА ФАСАДАХ ЗДАНИЙ И СООРУЖЕНИЙ ГОРОДА ТЮМЕНИ: РАЗНООБРАЗИЕ И ФАКТОРЫ ФОРМИРОВАНИЯ

Актуальность работы. Карбонатные коры, наросты и выцветы, формирующиеся на фасадах различных зданий и сооружений в результате выщелачивания компонентов строительных материалов, таких как цемент, бетон, известняк, являются наиболее распространенными видами техногенного минералообразования в условиях городской среды. В отличие от непрочных сталактитов и сталагмитов, формирование которых наблюдается только в определенных условиях, подобные образования широко распространены. Развитие карбонатных кор, наростов и выцветов на фасадах зданий не только свидетельствует о процессах разрушения связующих компонентов строительных конструкций, но и оказывает негативное воздействие на эстетическую привлекательность объектов городской архитектуры. Натёчные образования кальцита заполняют микротрещины и неровности поверхностей облицовочных материалов, что приводит к интенсификации процессов разрушения и требует проведения дорогостоящих мероприятий по очистке фасадов. Исследования, посвященные изучению карбонатных новообразований на фасадах различных зданий и сооружений, немногочисленны. Цель работы: выявление особенностей минерального состава, строения и возможных механизмов образования карбонатных кор и натеков, формирующихся на фасадах зданий и сооружений города Тюмени в различных условиях; определение факторов, способствующих данному явлению. Методы: выявление и систематизация объектов городской архитектуры, подверженных процессам формирования карбонатных новообразований, поляризационная и инвертированная микроскопия в прозрачных шлифах, СЭМ-ЭДС, рентгеноструктурный анализ. Результаты. Карбонатные коры и натеки существенно различаются по особенностям строения, минеральному составу и вероятным механизмам формирования в зависимости от конкретного местоположения. Четко разделяются коры, развивающиеся на вертикальных и горизонтальных поверхностях: первые – плоские, достаточно тонкие и имеют слоистую структуру, вторые – плотные и характеризуются глобулярным строением. Формирование карбонатных новообразований происходит при значительном участии живых организмов, а процессы биогенного осаждения кальцита происходят синхронно с хемогенным. Четких связей между возрастом или местоположением конкретных объектов и интенсивностью формирования карбонатных кор не выявлено; соответственно данный процесс скорее обусловлен конструктивными особенностями конкретных сооружений и качеством строительных материалов.

Conservation of epigenetic regulation by the MLL3/4 tumour suppressor in planarian pluripotent stem cells

Currently, little is known about the evolution of epigenetic regulation in animal stem cells. Here we demonstrate, using the planarian stem cell system to investigate the role of the COMPASS family of MLL3/4 histone methyltransferases that their function as tumor suppressors in mammalian stem cells is conserved over a long evolutionary distance. To investigate the potential conservation of a genome-wide epigenetic regulatory program in animal stem cells, we assess the effects of Mll3/4 loss of function by performing RNA-seq and ChIP-seq on the G2/M planarian stem cell population, part of which contributes to the formation of outgrowths. We find many oncogenes and tumor suppressors among the affected genes that are likely candidates for mediating MLL3/4 tumor suppression function. Our work demonstrates conservation of an important epigenetic regulatory program in animals and highlights the utility of the planarian model system for studying epigenetic regulation.

The HDAC6/8/10 inhibitor TH34 induces DNA damage-mediated cell death in human high-grade neuroblastoma cell lines

High histone deacetylase (HDAC) 8 and HDAC10 expression levels have been identified as predictors of exceptionally poor outcomes in neuroblastoma, the most common extracranial solid tumor in childhood. HDAC8 inhibition synergizes with retinoic acid treatment to induce neuroblast maturation in vitro and to inhibit neuroblastoma xenograft growth in vivo. HDAC10 inhibition increases intracellular accumulation of chemotherapeutics through interference with lysosomal homeostasis, ultimately leading to cell death in cultured neuroblastoma cells. So far, no HDAC inhibitor covering HDAC8 and HDAC10 at micromolar concentrations without inhibiting HDACs 1, 2 and 3 has been described. Here, we introduce TH34 (3-(N-benzylamino)-4-methylbenzhydroxamic acid), a novel HDAC6/8/10 inhibitor for neuroblastoma therapy. TH34 is well-tolerated by non-transformed human skin fibroblasts at concentrations up to 25 µM and modestly impairs colony growth in medulloblastoma cell lines, but specifically induces caspase-dependent programmed cell death in a concentration-dependent manner in several human neuroblastoma cell lines. In addition to the induction of DNA double-strand breaks, HDAC6/8/10 inhibition also leads to mitotic aberrations and cell-cycle arrest. Neuroblastoma cells display elevated levels of neuronal differentiation markers, mirrored by formation of neurite-like outgrowths under maintained TH34 treatment. Eventually, after long-term treatment, all neuroblastoma cells undergo cell death. The combination of TH34 with plasma-achievable concentrations of retinoic acid, a drug applied in neuroblastoma therapy, synergistically inhibits colony growth (combination index (CI) < 0.1 for 10 µM of each). In summary, our study supports using selective HDAC inhibitors as targeted antineoplastic agents and underlines the therapeutic potential of selective HDAC6/8/10 inhibition in high-grade neuroblastoma.

The influence of thermal annealing on structural properties of Ni nanotubes

The paper presents the results of studying the structural properties of Ni nanotubes affected by thermal annealing. Scanning electron microscopy, X-ray phase analysis and energy dispersive analysis were used to investigate the microstructure. An increase in the annealing temperature is found to lead to a change in the main crystallographic characteristics (unit cell parameter, crystallite size) and the appearance of new phases in the structure. The change in microarrays in the structure as a result of thermal annealing is of a two-stage nature: the first stage is characterized by an improvement in the crystal structure as a result of annealing defects; the second stage is characterized by an increase in micro-displacements in the crystal structure due to the appearance of two phases-the nickel oxide compound NiO2 and γ-Ni, whose contribution increases with the annealing temperature. At the same time, the formation of new phases in the crystal structure leads to a partial amorphization of the structure and the formation of outgrowths on tubes surface. The obtained knowledge can be applied to supplement the theory of thermal stability of nanostructures, as well as to assess their applicability in modern materials science.

MOCVD-derived GdYBCO tapes with smooth surface and low Rs based on a new self-heating technology

The metal organic chemical vapor deposition (MOCVD) method was used to prepare GdYBCO films on LaMnO3/ homo epitaxial-MgO/ ion-beam-assisted-deposition-MgO/ solution-deposition-planarization-Y2O3 buffered Hastelloy tapes. By adopting a simple self-heating technique, the substrates were heated by the joule effect after applying a heating current (Ih) through Hastelloy metal tapes. The effects of substrate temperature and (Gd, Y)/Ba ratio (rc) in the precursor on the biaxial texture, surface morphology and superconducting performance of GdYBCO films were systematically investigated by varying the values of Ih and rc. Needle-like outgrowths formed on the substrate surface were characterized using a scanning electron microscope, energy dispersive spectrometer and X-ray diffraction system. The results show that a high Ih or rc leads to the formation of needle-like outgrowths. Therefore, Ih and rc are crucial process parameters that control the growth of needle-like outgrowths on the surface of GdYBCO films. Three hundred nanometer thick GdYBCO films were prepared at different Ih and rc by the MOCVD process. At an Ih of 27.0 A and an rc of 0.6, the surface of the GdYBCO film was very smooth and dense, which can provide a good template for multiple depositions of GdYBCO films. The critical current density of the deposited 300 nm-thick GdYBCO film was 4.4 MA/cm2 (77 K, 0 T), which is attributed to good biaxial texture and appropriate film composition. Furthermore, the microwave surface resistance (77 K, 10 GHz) of the GdYBCO film was merely 0.581 mΩ.

Signaling systems affecting the severity of multiple osteochondromas.

Multiple osteochondromas (MO) syndrome is a dominant autosomal bone disorder characterized by the formation of cartilage-capped bony outgrowths that develop at the juxtaposition of the growth plate of endochondral bones. MO has been linked to mutations in either EXT1 or EXT2, two glycosyltransferases required for the synthesis of heparan sulfate (HS). The establishment of mouse mutants demonstrated that a clonal, homozygous loss of Ext1 in a wild type background leads to the development of osteochondromas. Here we investigate mechanisms that might contribute to the variation in the severity of the disease observed in human patients. Our results show that residual amounts of HS are sufficient to prevent the development of osteochondromas strongly supporting that loss of heterozygosity is required for osteochondroma formation. Furthermore, we demonstrate that different signaling pathways affect size and frequency of the osteochondromas thereby modulating the severity of the disease. Reduced Fgfr3 signaling, which regulates proliferation and differentiation of chondrocytes, increases osteochondroma number, while activated Fgfr3 signaling reduces osteochondroma size. Both, activation and reduction of Wnt/β-catenin signaling decrease osteochondroma size and frequency by interfering with the chondrogenic fate of the mutant cells. Reduced Ihh signaling does not change the development of the osteochondromas, while elevated Ihh signaling increases the cellularity and inhibits chondrocyte differentiation in a subset of osteochondromas and might thus predispose osteochondromas to the transformation into chondrosarcomas.

Unsuspected osteochondroma-like outgrowths in the cranial base of Hereditary Multiple Exostoses patients and modeling and treatment with a BMP antagonist in mice.

Hereditary Multiple Exostoses (HME) is a rare pediatric disorder caused by loss-of-function mutations in the genes encoding the heparan sulfate (HS)-synthesizing enzymes EXT1 or EXT2. HME is characterized by formation of cartilaginous outgrowths—called osteochondromas- next to the growth plates of many axial and appendicular skeletal elements. Surprisingly, it is not known whether such tumors also form in endochondral elements of the craniofacial skeleton. Here, we carried out a retrospective analysis of cervical spine MRI and CT scans from 50 consecutive HME patients that included cranial skeletal images. Interestingly, nearly half of the patients displayed moderate defects or osteochondroma-like outgrowths in the cranial base and specifically in the clivus. In good correlation, osteochondromas developed in the cranial base of mutant Ext1f/f;Col2-CreER or Ext1f/f;Aggrecan-CreER mouse models of HME along the synchondrosis growth plates. Osteochondroma formation was preceded by phenotypic alteration of cells at the chondro-perichondrial boundary and was accompanied by ectopic expression of major cartilage matrix genes -collagen 2 and collagen X- within the growing ectopic masses. Because chondrogenesis requires bone morphogenetic protein (BMP) signaling, we asked whether osteochondroma formation could be blocked by a BMP signaling antagonist. Systemic administration with LDN-193189 effectively inhibited osteochondroma growth in conditional Ext1-mutant mice. In vitro studies with mouse embryo chondrogenic cells clarified the mechanisms of LDN-193189 action that turned out to include decreases in canonical BMP signaling pSMAD1/5/8 effectors but interestingly, concurrent increases in such anti-chondrogenic mechanisms as pERK1/2 and Chordin, Fgf9 and Fgf18 expression. Our study is the first to reveal that the cranial base can be affected in patients with HME and that osteochondroma formation is amenable to therapeutic drug intervention.

An inhibitor of serine proteases, serpinb1a, modulates differentiation of PC12 cells but not cultured neurons

It was shown that serpinb1a is expressed during differentiation of PC12 cells induced by nerve growth factor (NGF). Here, we found that overexpression of serpinb1a in PC12 cells weakly but significantly increases PC12 survival during staurosporine-induced apoptosis. Immunoprecipitation of serpinb1a after its overexpression in PC12 showed that this protein interacts with active caspase-3 in both resting cells and cells that were stimulated by staurosporine. NGF-induced PC12 differentiation resulted in the formation of outgrowths and a considerable increase in caspase-3 activity in 24 h after the beginning of NGF treatment. This increase in the activity of caspase-3 lasted for at least 48 h. Overexpression of serpinb1a in PC12 cells suppressed the growth of neurites during NGF-induced differentiation; this effect was observed only at 48 h. Experiments performed with primary cultures of neocortical and hippocampal neurons showed that serpinb1a overexpression results in relatively weak changes in morphology: serpinb1a decreased the number of secondary dendrites in the cortical and average length of secondary dendrites in hippocampal neurons. The results of the experiments suggests that serpinb1a may interact with caspase-3 and influence the differentiation of PC12 cells but not neuronal cells.

The Hippo Pathway Regulates Stem Cells During Homeostasis and Regeneration of the FlatwormMacrostomum Lignano

The Hippo pathway orchestrates activity of stem cells during development and tissue regeneration and is crucial for controlling organ size. However, roles of the Hippo pathway in highly regenerative organisms, such as flatworms, are unknown. Here we show that knockdown of the Hippo pathway core genes in the flatworm Macrostomum lignano affects tissue homeostasis and causes formation of outgrowths through hyperproliferation of stem cells (neoblasts), and leads to disruption of allometric scaling during regeneration and increased size of regenerated parts. We further show that Yap, the downstream effector of the Hippo pathway, is a potential neoblast marker gene, as it is expressed in dividing cells in M. lignano and is essential for neoblast self-renewal. The phenotypes we observe in M. lignano upon knockdown of the Hippo pathway core genes and Yap are consistent with the known functions of the pathway in other model organisms and demonstrate that the Hippo pathway is functionally conserved between flatworms and mammals. This work establishes M. lignano as a productive model for investigation of the Hippo pathway.