Resistin induces monocyte-endothelial cell adhesion by increasing ICAM-1 and VCAM-1 expression in endothelial cells via p38MAPK-dependent pathway

Resistin, firstly reported as an adipocyte-specific hormone, is suggested to be an important link between obesity and diabetes. Recent studies have suggested an association between resistin and atherogenic processes. The adhesion of circulating monocytes to endothelial cells is a critical step in the early stages of atherosclerosis. The purpose of the present study was to investigate the effect of resistin on the adhesion of THP-1 monocytes to human umbilical vein endothelial cells (HUVECs) and the underlying mechanism. Our results showed that resistin caused a significant increase in monocyte adhesion. In exploring the underlying mechanisms of resistin action, we found that resistin-induced monocyte adhesion was blocked by inhibition of p38MAPK activation using SB203580 and SB202190. Furthermore, resistin increased the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) by HUVECs and these effects were also p38MAPK-dependent. Resistin-induced monocyte adhesion was also blocked by monoclonal antibodies against ICAM-1 and VCAM-1. Taken together, these results show that resistin increases both the expression of ICAM-1 and VCAM-1 by endothelial cells and monocyte adhesion to HUVECs via p38MAPK-dependent pathways.     

Integrated soil and plant phosphorus management for crop and environment in China. A review

In semi-arid grassland ecosystems, soil biogeochemical processes are controlled by seasonal and inter-annual rainfall variation and temperature, which may override the long-term impact of grazers on N availability and N dynamics. In a three-year (2004?C2006) case study of an Inner Mongolian grassland, we analysed time-integrated (ion-exchange resins) and instantaneous (soil mineral N extractions) inorganic N availability at three sites of varying grazing intensities and combined these data with information on soil water content (SWC), aboveground net primary productivity (ANPP) and plant N uptake. Additionally, the effects of rainfall and grazing on N-form availability (NO ₃ ^? -N, NH ₄ ⁺ -N) were considered. Grazing had less impact on N availability compared to seasonal and annual rainfall distribution. One of the three study years (2004) showed a grazing effect with higher resin-N availability at the ungrazed site compared to the heavily grazed site. Inorganic N availability was low in the driest year (2005) and highest in a year of average rainfall amount and favourable distribution (2004). In general, we found a positive relationship between inorganic N availability and both plant productivity and plant N uptake. Rainfall also controlled the plant available NO ₃ ^? -N and NH ₄ ⁺ -N pools; NH ₄ ⁺ -N dominated the available inorganic N-form in times of low SWC, while the available NO ₃ ^? -N increased with SWC. We observed N availability and plant productivity in a temporal synchronized pattern. Increased rainfall variability and land-use practices affecting SWC will likely alter N availability dynamics (and the relation of N-forms) and, therefore, important processes of semi-arid natural grassland carbon and N cycling.     

阿片类物质在中枢神经系统的免疫调控作用

内源及外源性阿片具有调节神经元与胶质细胞的功能,这些调节具有保护或损伤脑功能的双重作用。吗啡具有促进受病毒复制及继发感染的作用。另一方面,阿片受体中的ｋａｐｐａ受体可能具有保护神经元的作用。更深层次的研究应是了解阿片通过什么机制作用在胶质细胞和神经元上,藉此以促进研制出具有明显疗效的新药。     

Genome-wide comparative analysis of DNAJ genes and their co-expression patterns with HSP70s in aestivation of the sea cucumber Apostichopus japonicus

Functional & Integrative Genomics - DNAJ proteins function as co-chaperones of HSP70 and play key roles in cell physiology to promote protein folding and degradation, especially under...     

RNA结合蛋白调节mRNA稳定性的作用机制

免疫稳态的维持涉及多种细胞因子的基因表达调控,其中在转录后水平对mRNA稳定性的调控起重要作用。ARE(AU-rich element)位于mRNA 3'UTR(非编码区),富含AU碱基,某些RNA结合蛋白通过识别结合ARE影响mRNA的稳定性。本文综合最新研究,概述了TTP、HUR等RNA结合蛋白对mRNA稳定性的调节机制及其在信号通路中的作用。     

Preparation of (2S, 3R)-methyl-3-phenylglycidate using whole cells of Pseudomonas putida

Preparation of (2S, 3R)-methyl 3-phenylglycidate via enantioselective hydrolysis of racemic phenylglycidate was carried out using whole cells of Pseudomonas putida. Under optimal conditions (2S, 3R)-methyl-3-phenylglycidate could be got with ee value 99 and 48% chemical yield.     

生物素-亲和素偶联探针蛋白芯片检测技术

自行制备一种新型生物素-亲和素偶联探针分子并用于反相蛋白芯片的检测。首先, 将生物素-羊抗鼠IgG与亲和素按照不同比例混合后与鼠IgG蛋白芯片反应, 观察荧光信号的放大情况; 然后以鼠IgG-羊抗鼠IgG体系为研究模式, 对反相蛋白芯片的制备条件进行了考察和优化, 包括荧光分子的非特异性吸附、点样缓冲液的选择以及蛋白的活性等。最后, 采用此偶联探针对反相蛋白芯片进行了检测。结果表明, BSA缓冲液制备的反相蛋白芯片可以防止非特异性吸附, 并有利于保持固定蛋白活性和提高检测限; 另外, 与传统的与生物素-亲和素检测技术相比, 采用生物素-亲和素偶联探针对反相芯片的检测限可以提高4倍左右。表明亲和素-生物素偶联探针成本低、易于合成、并可以与其它的信号放大技术联用进一步提高检测的灵敏度, 有望用于蛋白质芯片的检测。     

Pioglitazone suppresses advanced glycation end product-induced expression of plasminogen activator inhibitor-1 in vascular smooth muscle cells

Advanced glycation end products (AGEs) play an important role in vascular complications of diabetes, including fibrinolytic abnormalities.Pioglitazone, a peroxisome proliferator-activated receptor gamma (PPARΥ) agonist, has recently been shown to reduce circulating plasminogen activator inhibitor-1 (PAI-1) levels in diabetes mellitus. In the present study, we investigated the effects of pioglitazone on the expression of local PAI-1 in rat vascular smooth muscle cells (VSMCs) induced by AGEs and the underlying mechanism. The result showed that AGEs could enhance the PAI-1 expression by 5.1-fold in mRNA and 2.7-fold in protein level, as evaluated by real-time RT-PCR and Western blotting,respectively. Pioglitazone was found to down-regulate the AGE-stimulated PAI-1 expression in VSMCs. However, these inhibitory effects were partially attenuated by the PPARΥ antagonist, GW9662. Furthermore, we found that AGEs induced a rapid increase in phosphorylation and activation of extracellular signal-regulated protein kinase 1/2 (ERK 1/2). The ERK kinase inhibitor, UO126, partially prevented the induction of PAI-1 by AGEs. Moreover, pioglitazone was also found to inhibit the phosphorylation of ERKi/2. Taken together, it was concluded that pioglitazone could inhibit AGE-induced PAI-1 expression, which was mediated by the ERK1/2 and PPARΥ pathways. Our findings suggestedpioglitazone had a therapeutic potential in improving fibrinolytic activity, and consequently preventing thromboembolic complications of diabetes and cardiovascular disease.     

雌激素信号通路概述

过去几十年,人们一直认为雌激素信号通路是雌激素与细胞核中的雌激素受体(ER)结合,作用于雌激素受体反应元件调节基因表达,从而改变细胞功能。雌激素不但与核ER结合,也能与膜ER结合激活PI3K信号通路。G蛋白偶联受体(GPR30)也能与雌激素结合,激活PI3K信号通路。雌激素通过结合不同雌激素受体改变细胞生理功能。我们对雌激素信号通路做简要综述。