SUMMARYTGF/BMP signaling regulates the fate of multipotential cranial neural crest (CNC) cells during tooth and jawbone formation as these cells differentiate into odontoblasts and osteoblasts, respectively. The functional significance of SMAD4, the common mediator of TGF/BMP signaling, in regulating the fate of CNC cells remains unclear. In this study, we investigated the mechanism of SMAD4 in regulating the fate of CNC-derived dental mesenchymal cells through tissue-specific inactivation of Smad4. Ablation of Smad4 results in defects in odontoblast differentiation and dentin formation. Moreover, ectopic bone-like structures replaced normal dentin in the teeth of Osr2-IresCre;Smad4 fl/fl mice. Despite the lack of dentin, enamel formation appeared unaffected in Osr2-IresCre;Smad4 fl/fl mice, challenging the paradigm that the initiation of enamel development depends on normal dentin formation. At the molecular level, loss of Smad4 results in downregulation of the WNT pathway inhibitors Dkk1 and Sfrp1 and in the upregulation of canonical WNT signaling, including increased -catenin activity. More importantly, inhibition of the upregulated canonical WNT pathway in Osr2-IresCre;Smad4 fl/fl dental mesenchyme in vitro partially rescued the CNC cell fate change. Taken together, our study demonstrates that SMAD4 plays a crucial role in regulating the interplay between TGF/BMP and WNT signaling to ensure the proper CNC cell fate decision during organogenesis.

Hexagonal single crystal WO(3) nanorods with dominant (001) and (1 ̄10) facets were synthesized, which exhibited high adsorption capacities for organic dyes.

Aspirin (acetylsalicylic acid, ASA) has been shown to improve bone marrow mesenchymal stem cell-based calvarial bone regeneration by promoting osteogenesis and inhibiting osteoclastogenesis. However, it remains unknown whether aspirin influences other immune cells during bone formation. In the present study, we investigated whether ASA treatment influenced macrophage activation during the LPS inducement. We found that ASA could downregulate the expressions of iNOS and TNF-α both in mouse peritoneum macrophages and RAW264.7 cells induced by LPS via the IκK/IκB/NF-κB pathway and a COX2/PGE2/EP2/NF-κB feedback loop, without affecting the expressions of FIZZ/YM-1/ARG1 induced by IL-4. Furthermore, we created a rat mandibular bone defect model and showed that ASA treatment improved bone regeneration by inhibiting LPS-induced macrophage activation in the early stages of inflammation. Taken together, our results indicated that ASA treatment was a feasible strategy for improving bone regeneration, particularly in inflammatory conditions.

SummaryThe Yellow Sea region is of high global importance for waterbird populations, but recent systematic bird count data enabling identification of the most important sites are relatively sparse for some areas. Surveys of waterbirds at three sites on the coast of southern Jiangsu Province, China, in 2014 and 2015 produced peak counts of international importance for 24 species, including seven globally threatened and six Near Threatened species. The area is of particular global importance for the ‘Critically Endangered’ Spoon-billed Sandpiper Calidris pygmaea (peak count across all three study sites: 62 in spring [2015] and 225 in autumn [2014] and ‘Endangered’ Spotted Greenshank Tringa guttifer (peak count across all three study sites: 210 in spring [2014] and 1,110 in autumn [2015]). The southern Jiangsu coast is therefore currently the most important migratory stopover area in the world, in both spring and autumn, for both species. Several serious and acute threats to waterbirds were recorded at these study sites. Paramount is the threat of large-scale land claim which would completely destroy intertidal mudflats of critical importance to waterbirds. Degradation of intertidal mudflat habitats through the spread of invasive Spartina, and mortality of waterbirds by entrapment in nets or deliberate poisoning are also real and present serious threats here. Collisions with, and displacement by, wind turbines and other structures, and industrial chemical pollution may represent additional potential threats. We recommend the rapid establishment of effective protected areas for waterbirds in the study area, maintaining large areas of open intertidal mudflat, and the urgent removal of all serious threats currently faced by waterbirds here.

The self-assembly synthesis of tungsten oxide quantum dots with enhanced optical properties A one-pot microwave-assisted methodology was explored to fabricate ultrafi ne and monodispersed WO 3 quantum dots, with excellent thermal/photonic stabilities favorable for photoluminescence blue emission and photochromic performance. See Guisheng Li, Michael K. H. Leung et al., J. Mater. Chem. C, 2015, 3, 3280. 3280 | J. Mater. Chem. C, 2015, 3, 3280--3285This journal isIn the present paper, a one-pot microwave-assisted approach was explored for self-assembly fabrication of ultrafine tungsten oxide (WO 3 ) quantum dots (QDs). The as-obtained WO 3 QDs were ultrafine, with a quantum size ranging from 2 to 3 nm. Such ultrafine WO 3 QDs exhibited significant thermal/photonic stabilities, which are favorable for blue photoluminescence emission and photochromism properties. The WO 3 QDs could be well maintained in ethylene glycol at 120 1C for 4 days, without the occurrence of aggregation phenomena. It took about 10 s for the colorless aqueous suspension of WO 3 QDs to turn blue under solar-light irradiation. A negligible decrease rate (2.7%) was observed for the relative luminescence emission intensity of WO 3 QDs after being irradiated by UV light (365 nm) for 24 hours. Such greatly enhanced photochromism was attributed to both the exposed reactive sites and surface oxygen vacancies of ultrafine WO 3 QDs.