Effect of protocatechuic acid from Alpinia oxyphylla on proliferation of human adipose tissue-derived stromal cells in vitro

The effect of protocatechuic acid (PCA) from Alpinia oxyphylla and catapol from Rehmannia on the proliferation capacity of human adipose tissue-derived stromal cells (hADSCs) was investigated in vitro. Cell counts showed that treatment of hADSCs with PCA for 48 h increased the cell number in a dose-dependent manner, while no obvious effect of catapol on the proliferation of hADSCs was observed. In addition, the cell number of hADSCs treated by 1.5 mM PCA increased in a time-dependent manner. The flow cytometric analysis of DNA content demonstrated the cell cycle progress from the G0/G1 phase to the S phase. Western blot analysis revealed the elevated expression of cyclin D1 in hADSCs induced by PCA treatment. Cyclin D1-siRNA transfection significantly inhibit the promotion of cell proliferation by PCA. Furthermore, the flow cytometric analysis of the cell surface antigens and the multidifferential potential tests of PCA-treated hADSCs showed that the cells retained their functional characteristics of multipotential mesenchymal progenitors. It is concluded that PCA can effectively up-regulate the proliferation of hADSCs.     

Rnf20 deficiency in adipocyte impairs adipose tissue development and thermogenesis

RNF20,an E3 ligase critical for monoubiquitination of histone H2B at lysine 120 (H2Bub),has been implicated in the regulation of various cellar processes;however,its physiological roles in adipocytes remain poorly characterized.Here,we report that the adipocyte-speci-fic knockout of Rnf20 (ASKO) in mice led to progressive fat loss,organomegaly and hyperinsulinemia.Despite signs of hyperinsulinemia,normal insulin sensitivity and improved glucose tolerance were observed in the young and aged CD-fed ASKO mice.In addition,high-fat diet-fed ASKO mice developed severe liver steatosis.More-over,we observed that the ASKO mice were extremely sensitive to a cold environment due to decreased expression levels of brown adipose tissue (BAT) selec-tive genes,including uncoupling protein 1 (Ucp1),and impaired mitochondrial functions.Significantly decreased levels of peroxisome proliferator-activated receptor gamma (Ppary) were observed in the gonadal white adipose tissues (gWAT) from the ASKO mice,suggesting that Rnf20 regulates adipogenesis,at least in part,through Ppary.Rosiglitazone-treated ASKO mice exhibited increased fat mass compared to that of the non-treated ASKO mice.Collectively,our results illus-trate the critical role of RNF20 in control of white and brown adipose tissue development and physiological function.     

Serine metabolism antagonizes antiviral innate immunity by preventing ATP6V0d2-mediated YAP lysosomal degradation

1. Download : Download high-res image (200KB)
2. Download : Download full-size image

     

The fine structure of the mitotic chromosome core (scaffold) of Trilophidia annulata

We studied the fine structure of mitotic chromosome cores (scaffolds) in spermatogonia of Trilophidia annulata by the squash method, the silver staining technique, and light and electron microscopy. The chromosome core seemed to be helically coiled when viewed in the light microscope. Electron microscopic in situ observations on the squash preparations transferred from slides to grids indicated that the core was basically a compact network of fibres, rather than a simple coiled structure. In the core, there were two longitudinal main fibres, which were relatively thick and twined about one another. Each of the main fibres consisted of thinner fibres. The twined fibres composed the network structure of the core. Based on these observations, we discuss the morphological features of the core.by T.C. Hsu