Influence of 1α, 25-dihydroxyvitamin D3 [1, 25(OH)2D3] on the expression of Sox 9 and the transient receptor potential vanilloid 5/6 ion channels in equine articular chondrocytes

Background Sox 9 is a major marker of chondrocyte differentiation. When chondrocytes are cultured in vitro they progressively de-differentiate and this is associated with a decline in Sox 9 expression. The active form of vitamin D, 1, 25 (OH)2D3 has been shown to be protective of cartilage in both humans and animals. In this study equine articular chondrocytes were grown in culture and the effects of 1, 25 (OH)2D3 upon Sox 9 expression examined. The expression of the transient receptor potential vanilloid (TRPV) ion channels 5 and 6 in equine chondrocytes in vitro, we have previously shown, is inversely correlated with de-differentiation. The expression of these channels in response to 1, 25 (OH)2D3 administration was therefore also examined. Results The active form of vitamin D (1, 25 (OH)2D3) when administered to cultured equine chondrocytes at two different concentrations significantly increased the expression of Sox 9 at both. In contrast 1, 25 (OH)2D3 had no significant effect upon the expression of either TRPV 5 or 6 at either the protein or the mRNA level. Conclusions The increased expression of Sox 9, in equine articular chondrocytes in vitro, in response to the active form of vitamin D suggests that this compound could be utilized to inhibit the progressive de-differentiation that is normally observed in these cells. It is also supportive of previous studies indicating that 1α, 25-dihydroxyvitamin D3 can have a protective effect upon cartilage in animals in vivo. The previously observed correlation between the degree of differentiation and the expression levels of TRPV 5/6 had suggested that these ion channels may have a direct involvement in, or be modulated by, the differentiation process in vitro. The data in the present study do not support this

The Transient Receptor Potential Ion Channel TRPV6 Is Expressed at Low Levels in Osteoblasts and Has Little Role in Osteoblast Calcium Uptake

Background: TRPV6 ion channels are key mediators of regulated transepithelial absorption of Ca2+ within the small intestine. Trpv6-/- mice were reported to have lower bone density than wild-type littermates and significant disturbances in calcium homeostasis that suggested a role for TRPV6 in osteoblasts during bone formation and mineralization. TRPV6 and molecules related to transepithelial Ca2+ transport have been reported to be expressed at high levels in human and mouse osteoblasts. Results: Transmembrane ion currents in whole cell patch clamped SaOS-2 osteoblasts did not show sensitivity to ruthenium red, an inhibitor of TRPV5/6 ion channels, and 45Ca uptake was not significantly affected by ruthenium red in either SaOS-2 (P = 0.77) or TE-85 (P = 0.69) osteoblastic cells. In contrast, ion currents and 45Ca uptake were both significantly affected in a human bronchial epithelial cell line known to express TRPV6. TRPV6 was expressed at lower levels in osteoblastic cells than has been reported in some literature. In SaOS-2 TRPV6 mRNA was below the assay detection limit; in TE-85 TRPV6 mRNA was detected at 6.90±1.9 × 10−5 relative to B2M. In contrast, TRPV6 was detected at 7.7±3.0 × 10−2 and 2.38±0.28 × 10−4 the level of B2M in human carcinoma-derived cell lines LNCaP and CaCO-2 respectively. In murine primary calvarial osteoblasts TRPV6 was detected at 3.80±0.24 × 10−5 relative to GAPDH, in contrast with 4.3±1.5 × 10−2 relative to GAPDH in murine duodenum. By immunohistochemistry, TRPV6 was expressed mainly in myleocytic cells of the murine bone marrow and was observed only at low levels in murine osteoblasts, osteocytes or growth plate cartilage. Conclusions: TRPV6 is expressed only at low levels in osteoblasts and plays little functional role in osteoblastic calcium uptake

Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe

Culex quinquefasciatus quinquefasciatus strain:Thai Transcriptome or Gene expression

This study used quantitative RNA-Sequencing analyses to explore blood meal induced regulation of chemosensory gene families in the antennae of 6 days post-emergence C. quinquefasciatus females, 24 hours post blood feeding

Culex quinquefasciatus quinquefasciatus strain:Thai Transcriptome or Gene expression

This study used quantitative RNA-Sequencing analyses to explore blood meal induced regulation of chemosensory gene families in the antennae of 6 days post-emergence C. quinquefasciatus females, 24 hours post blood feeding

Management of bacterial blotch: the casing, cultivar and more

Bacterial blotch diseases lead to coloured spots on the caps of mushrooms. This not only leaves the crop unmarketable, brt also reduces the post-harvest shelf-life of the crop. 'Casing soil resilience to bacterial blotch 'was a four-year research project at Wageningen University & Research, which described the role of the casing soil and cultivar on bacterial blotch outbreaks (see also MB102/2020). Here we summarize the newest findings together with suggested management strategies for blotch outbreaks

Nieuwe inzichten in de ziekteverwekkers van bacterievlekken

'Weerstand van de dekaarde tegen bacterievlekkenziekte' is een project bij Wageningen University & Research (WUR), dat wordt uitgevoerd in samenwerking met verschillende leden van de Nederlandse toeleveringsketen voor champignons. Over een periode van vier jaar heeft dit project een breed scala aan vragen over bacterievlekken bij champignons beantwoord. Zo is kennis verzameld over de identificattie van de veroorzakers, detectie van de ziekteverwekkers, infectiedynamiek, bron van introductie, het effect van verschillende soorten dekaarde en de weerstand van dekaarde tegen bacterievlekken. In deze bijdrage vatten we de belangrijkste bevindingen van het project samen

Identification, diagnostics and infection dynamics of bacterial blotch pathogens

'Casing soil resilience to bacterial blotch' is an ongoing project at Wageningen University & Research (WUR), running in collaboration with various members of the Dutch mushroom supply-chain industry. Over the course of four years, this project has answered a broad-range of questions about bacterial blotch diseases of mushrooms. Research was done to generate knowledge on the identification of the causative agents, detection of blotch pathogens, infection dynamics, source of introduction, effect of different casing soils, and casing soil resilience to blotch outbreaks. Here we summarize the most significant findings from the project

Circular alternatives to peat in growing media: A microbiome perspective

Peat use in horticulture is associated with a large ecological footprint. Peat is the predominant growing media in Europe. Modern cropping systems rely heavily on dynamic interactions of the crop with the microorganisms in the growing media and yet, in the search for sustainable peat-alternatives, the microbiome of the growing media has often been ignored. In mushroom cultivation, peat is a prime determinant of productivity, in the form of a casing soil which supplies beneficial microbes. In this study we describe the microbial composition, interactions, and activity of four circular substrates used to proportionally replace peat in mushroom growing media. We also evaluate various physico-chemical characteristics of the peat-alternatives. We characterize the impact of sanitary pre-treatments such as steaming and acidification on the microbiome as well as the agronomical performance of the peat-reduced growing media. We found that grass fibres from agricultural residue streams, peat-moss farmed in degraded peatlands, and spent casing soil recycled from previous cultivation cycles can be used to successfully replace peat in mushroom growing media. Peat moss and spent casing were expectedly similar to peat in physical, chemical, and microbiological properties. However, the grass fibres had unique characteristics, such as high organic matter content, low water holding capacity and a diverse and competitive microbiome. Pretreatment of the substrates by acidification and steaming significantly affected the microbiome, and reduced the presence of pests, pathogens and competitive fungi in the peat-reduced media. Strong trade-offs existed between the productivity and disease pressure in the circular cropping system, which are also governed by the microbial composition of the growing media. Knowledge on the accessibility, sustainability, and economic viability of these peat-alternatives will further determine the transition away from peat use and towards sustainable growing media