Discovery and functional assessment of a novel adipocyte population driven by intracellular Wnt/ß-catenin signaling in mammals.

Wnt/ß-catenin signaling has been well established as a potent inhibitor of adipogenesis. Here, we identified a population of adipocytes that exhibit persistent activity of Wnt/ß-catenin signaling, as revealed by the Tcf/Lef-GFP reporter allele, in embryonic and adult mouse fat depots, named as Wnt+ adipocytes. We showed that this ß-catenin-mediated signaling activation in these cells is Wnt ligand- and receptor-independent but relies on AKT/mTOR pathway and is essential for cell survival. Such adipocytes are distinct from classical ones in transcriptomic and genomic signatures and can be induced from various sources of mesenchymal stromal cells including human cells. Genetic lineage-tracing and targeted cell ablation studies revealed that these adipocytes convert into beige adipocytes directly and are also required for beige fat recruitment under thermal challenge, demonstrating both cell autonomous and non-cell autonomous roles in adaptive thermogenesis. Furthermore, mice bearing targeted ablation of these adipocytes exhibited glucose intolerance, while mice receiving exogenously supplied such cells manifested enhanced glucose utilization. Our studies uncover a unique adipocyte population in regulating beiging in adipose tissues and systemic glucose homeostasis.

Preliminary assessment on exposure of four typical populations to potentially toxic metals by means of skin wipes under the influence of haze pollution.

To investigate the exposure risk of human beings to nine potentially toxic metals (PTMs), namely, Cu, Cr, Zn, As, Cd, Pb, Ni, Mn, and Co, skin wipe samples were collected from four types of populations, namely, children, undergraduates, security guards, and professional drivers, under different haze pollution levels in Xinxiang, China by using Ghost wipes. The Ghost wipes were quantitatively analyzed by inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion. Generally, Zn (ND-1350µg/m2 for undergraduates, ND-2660µg/m2 for security guards, ND-2460µg/m2 for children, and ND-2530µg/m2 for professional drivers) showed the highest concentration among the four populations, followed by Cu (0.02-83.4µg/m2 for undergraduates, ND-70.2µg/m2 for security guards, 23.2-487µg/m2 for children, and ND-116µg/m2 for professional drivers). As (ND-5.7µg/m2 for undergraduates, ND-2.3µg/m2 for security guards, ND-21.1µg/m2 for children, and ND-11.0µg/m2 for professional drivers) and Co (ND-6.0µg/m2 for undergraduates, ND-7.9µg/m2 for security guards, ND-13.4µg/m2 for children, and ND-2.1µg/m2 for professional drivers) showed the lowest concentrations in all populations. Remarkable differences were found among the four populations and PTM levels decreased in the following order: children, professional drivers, security guards, and undergraduates. Gender variation was discovered for undergraduates and children. Generally, PTM contamination in skin wipes collected during a light haze pollution level was generally higher than that during a heavy haze pollution level, but PTM contamination was comparable between the two haze pollution levels for children. Non-carcinogenic exposure risks to As, Cd, and Pb for all populations were higher than those for the other six elements but all of them were within the acceptable safety threshold, indicating no apparent non-carcinogenic risk.