肝纤维化中肌成纤维细胞的作用及TGF-β/Smads通路的研究进展

肌成纤维细胞(myofibrobasts)是一种多起源的异质性细胞,在肝纤维化过程和愈伤反应(wound-healing response)中扮演重要角色.TGF-β /Smads通路作为体内重要的信号调节通路,对肝纤维化过程具有关键的调节作用,现已成为国内外近年来的研究热点.对肌成纤维细胞的来源以及影响其分化的因素,TGF-β /Smads通路与调控的研究进展,以及肝纤维化的治疗进行了较为全面的综述,并就肝纤维化今后研究的主要发展方向进行了展望.     

Structural basis of RGD-hirudin binding to thrombin: Tyr3 and five C-terminal residues are crucial for inhibiting thrombin activity

Background

p300/CBP associating factor (PCAF, also known as KAT2B for lysine acetyltransferase 2B) is a catalytic subunit of megadalton metazoan complex ATAC (Ada-Two-A containing complex) for acetylation of histones. However, relatively little is known about the regulation of the enzymatic activity of PCAF.

Results

Here we present two dimeric structures of the PCAF acetyltransferase (HAT) domain. These dimerizations are mediated by either four-helical hydrophobic interactions or a ß-sheet extension. Our chemical cross-linking experiments in combined with site-directed mutagenesis demonstrated that the PCAF HAT domain mainly forms a dimer in solution through one of the observed interfaces. The results of maltose binding protein (MBP)-pulldown, co-immunoprecipitation and multiangle static light scattering experiments further indicated that PCAF dimeric state is detectable and may possibly exist in vivo.

Conclusions

Taken together, our structural and biochemical studies indicate that PCAF appears to be a dimer in its functional ATAC complex.     

黄附子中糖复合物的初步分析

生药中糖复合物研究是２１世纪生物科学热点之一。本文首次报道了附子中糖复合物的研究结果。我们采用饱和硫酸铵沉淀、乙醇分级沉淀及ＤＥＡＢ－Ｃ３２层析方法,从黄附子中分离出三种组分,通过鉴定发现：组分Ｉ主要为糖蛋白,组分Ⅱ主要含酸性多糖,组分Ⅲ可能是淀粉。此研究结果为全面深入地研究和开发附子提供了参考依据。     

附子多糖FI的分离纯化及部分理化性质研究

白附片经热水抽提、Sevag法脱蛋白、乙醇沉淀、DEAE- C32柱层析分离 ,再通过 Sephadex G- 2 0 0柱层析进一步纯化 ,得到一种纯白色粉末状多糖 ,糖含量为 97% ,平均分子量为 2 .6× 10 5,熔点为 2 70℃。经完全酸水解、薄层层析、红外光谱分析 ,证明为葡聚糖。     

HIV-1 Tat increases BAG3 via NF-κB signaling to induce autophagy during HIV-associated neurocognitive disorder

The human immunodeficiency virus-1 (HIV-1) regulatory protein Tat plays an important role during HIV-1-associated neurocognitive disorders (HAND) by inducing neuronal autophagy. In this study, we used immunohistochemistry, immunofluorescence, western blot, qRT-PCR, and RNA interference to elucidate the involvement of Bcl-2-associated athanogene 3 (BAG3) in the pathogenesis of HIV-1 Tat-induced autophagy during HAND. We found that BAG3 expression is elevated in astrocytes in frontal cortex of macaques infected with simian immunodeficiency virus-human immunodeficiency chimeric virus (SHIV). In addition, in human primary glioblastoma cells (U87), HIV-1 Tat upregulated BAG3 in an NF-κB-dependent manner to induce autophagy. Importantly, suppression of BAG3 or inhibition of NF-κB activity reversed the HIV-1 Tat-induced autophagy. These results indicate that HIV-1 Tat induces autophagy by upregulating BAG3 via NF-κB signaling, which suggests BAG3 and NF-κB could potentially serve as novel targets for HAND therapies.     

Phosphorus-fertilisation has differential effects on leaf growth and photosynthetic capacity of Arachis hypogaea L.

Plant and Soil - The objectives of this study were to assess how Arachis hypogaea L. (peanut or groundnut) responds to different P supplies in terms of growth and photosynthesis, and to determine...     

Morphology and mechanics of chondroid cells from human adipose-derived Stem cells detected by atomic force microscopy

Chondroid cell from human adipose-derived stem cells (ADSCs) has emerged as an alternative treatment option for articular cartilage defects. Herein, we successfully compared ADSCs, normal chondrocytes, and chondroid cells. The comparative study of ADSCs and chondroid cells revealed type II collagen (COL II) and glycosaminoglycans expression of chondroid cells were similar to those in normal chondrocytes, and much higher than ADSCs. Using atomic force microscope (AFM) and laser confocal scanning microscopy (LCSM), we compared the differences in morphology, mechanical properties, and F-actin distribution between chondroid cells and normal chondrocytes. Our results showed no differences observed between these two types of cells regarding morphology, stiffness, and F-actin distribution. However, found that the adhesion force in chondroid cells was lower than that in normal chondrocytes. Taken together, our AFM and LCSM analyses suggest that the lower adhesion force in chondroid cells may contribute to the dedifferentiation of ADSC-derived chondroid cells. Future examination of surface adhesion force-related protein expression will likely provide new insight into the molecular mechanisms underlying the dedifferentiation of ADSC-derived chondroid cells.