The microRNA-29 family in cartilage homeostasis and osteoarthritis

MicroRNAs have been shown to function in cartilage development and homeostasis, as well as in progression of osteoarthritis. The objective of the current study was to identify microRNAs involved in the onset or early progression of osteoarthritis and characterise their function in chondrocytes. MicroRNA expression in mouse knee joints post-DMM surgery was measured over 7 days. Expression of miR-29b-3p was increased at day 1 and regulated in the opposite direction to its potential targets. In a mouse model of cartilage injury and in end-stage human OA cartilage, the miR-29 family were also regulated. SOX9 repressed expression of miR-29a-3p and miR-29b-3p via the 29a/b1 promoter. TGFβ1 decreased expression of miR-29a, b and c (3p) in primary chondrocytes, whilst IL-1β increased (but LPS decreased) their expression. The miR-29 family negatively regulated Smad, NFκB and canonical WNT signalling pathways. Expression profiles revealed regulation of new WNT-related genes. Amongst these, FZD3, FZD5, DVL3, FRAT2, CK2A2 were validated as direct targets of the miR-29 family. These data identify the miR-29 family as microRNAs acting across development and progression of OA. They are regulated by factors which are important in OA and impact on relevant signalling pathways

Effect of silica on the catalytic destruction of chlorinated organics over V2O5/TiO2 catalysts

In the present work, the contribution of silica doping to the catalytic activity of V2O5/TiO2 based catalysts in the decomposition of chlorinated organic materials and on the formation of possible by by-products was investigated. The influence of vanadium loading on surface structures of differently supported materials has been systematically investigated by XRD, BET, Raman spectroscopy and H2-TPR. These studies demonstrated that the V2O5 supported on either TiO2/WO3 or TiO2/WO3/SiO2 is very active for the oxidation of o-DCB, a probe molecule for aromatic compounds which is present in flue gas. Silica was found to form a highly dispersed amorphous phase on the support surface, which strongly affects the structural degradation phenomena, delaying the collapse of surface area, that is particularly significant at high vanadium content. The presence of silica on the support influences the distribution of VOx species. Since it was demonstrated that support surfaces predominantly covered with highly dispersed vanadium lead to high activity, in spite of the lower ability of SiO2 to spread metal oxides, the higher stability of silica containing materials, while preserving surface area, favors vanadium dispersion and leads to superior catalytic performance

The effect of the nature of vanadium species on chlorinated organics total oxidation over TiO2 supported catalysts

In the present work, the nature of the vanadium species formed on titanium catalysts at different vanadium loading was related to the catalyst behaviour for the deep oxidation of o-dichorobenzene. Chemical physical characterization results indicated that at vanadium loading up to 3% the titanium surface was covered with dispersed V5+ species in tetrahedral and octahedral coordination, while increasing the vanadium content the presence of highly dispersed V5+ species decreased, and additional formation of bulk V2O5 was observed. Catalytic tests indicated that the optimal loading of vanadium was 3%, suggesting that active phases are highly dispersed vanadium species on titania. Moreover, it was observed that incompletely oxidized products, such as dichloro maleic anhydride (2,5 furandione 3,4 dichloro) were formed in all catalysts and the concentration of these by-products increased with vanadium loading. Since the introduction of basic sites on the catalyst surface promoted DCMA formation, this effect was ascribed to the change of acid-basic properties of catalysts due to the increasing of vanadium in the system