GroEL1, from Chlamydia pneumoniae, Induces Vascular Adhesion Molecule 1 Expression by p37(AUF1) in Endothelial Cells and Hypercholesterolemic Rabbit

The expression of vascular adhesion molecule-1 (VCAM-1) by endothelial cells may play a major role in atherogenesis. The actual mechanisms of chlamydia pneumoniae (C. pneumoniae) relate to atherogenesis are unclear. We investigate the influence of VCAM-1 expression in the GroEL1 from C. pneumoniae-administered human coronary artery endothelial cells (HCAECs) and hypercholesterolemic rabbits. In this study, we constructed the recombinant GroEL1 from C. pneumoniae. The HCAECs/THP-1 adhesion assay, tube formation assay, western blotting, enzyme-linked immunosorbent assay, actinomycin D chase experiment, luciferase reporter assay, and immunohistochemical stainings were performed. The results show that GroEL1 increased both VCAM-1expression and THP-1 cell adhesives, and impaired tube-formation capacity in the HCAECs. GroEL1 significantly increased the VCAM-1 mRNA stability and cytosolic AU-binding factor 1 (AUF1) level. Overexpression of the p37(AUF1) significantly increased VCAM-1 gene expression in GroEL1-induced bovine aortic endothelial cells (BAECs). GroEL1 prolonged the stability of VCAM-1 mRNA by increasing both p37(AUF1) and the regulation of the 5' untranslated region (UTR) of the VCAM-1 mRNA in BAECs. In hypercholesterolemic rabbits, GroEL1 administration enhanced fatty-streak and macrophage infiltration in atherosclerotic lesions, which may be mediated by elevated VCAM-1 expression. In conclusion, GroEL1 induces VCAM-1 expression by p37(AUF1) in endothelial cells and enhances atherogenesis in hypercholesterolemic rabbits.     

Resveratrol reduces infarct size and improves ventricular function after myocardial ischemia in rats

The purpose of this study was to investigate the effect of resveratrol, a polyphenol present in grapes and red wine, on ventricular remodeling after myocardial infarction (MI) in rats. After permanent ligation of the left anterior descending artery, surviving rats were randomly allocated to three groups and treated with 1 mg/kg/day resveratrol (R-1 group), 0.1 mg/kg/day resveratrol (R-0.1 group), or vehicles (control group) administered by intraperitoneal injection once daily for four weeks. We examined the effects of resveratrol by echocardiography, hemodynamic studies, histologic examinations, and real-time quantitative polymerase chain reaction. The R-1 group had significantly increased fractional shortening of the left ventricle, ameliorated left ventricular dilatation, reduced left ventricular end-diastolic pressure, and reduced infarct size. In contrast, the R-0.1 group experienced no beneficial effects on myocardial infarction. The R-1 group also had significantly attenuated expression of myocardial atrial natriuretic peptide and transforming growth factor-beta1 mRNAs. This study indicates that resveratrol is a potent cardioprotective agent in MI rats. Its cardioprotective effects may be due to a reduction of atrial natriuretic peptide and transforming growth factor-beta1, which are known to protect the heart from detrimental remodeling.     

Physiological and chemical indicators for early and late stages of sepsis in conscious rats

Endotoxin shock is a major cause of death in patients with septicemia. Endotoxin induces nitric oxide (NO) production and causes tissue damage. In addition, the release of oxygen free radicals has also been observed in endotoxin shock and was found to be responsible for the occurrence of multiple organ failure. The purpose of the present study was to evaluate suitable indicators for early and late stages of endotoxin shock. The experiments were designed to induce endotoxin shock in conscious rats by means of anEscherichia coli lipopolysaccharide (LPS) injection. Arterial pressure (AP) and heart rate (HR) were continuously monitored for 72 h after LPS administration. The maximal decrease in AP and increase in HR and nitrate/nitrite level occurred at 9–12 h following LPS administration. The white blood cell (WBC) count had decreased at 3 h. Hydroxyl radical (methyl guanidine, MG) decreased rapidly after LPS administration. Plasma levels of blood urea nitrogen (BUN), creatinine (Cr), lactic dehydrogenase (LDH), creatine phosphokinase (CPK), and glutamic oxaloacetic transaminase increased before the rise of amylase. Our results suggest that changes in AP, HR, WBC, free radicals, and chemical substances (BUN, Cr) can possibly serve as approximate indicators for the early stage of endotoxin shock. Severe multiple organ damage may be caused by amylase release in the late stage of endotoxin shock.     

Uncovering the regeneration strategies of zebrafish organs: a comprehensive systems biology study on heart,cerebellum, fin,and retina regeneration

Background

Regeneration is an important biological process for the restoration of organ mass, structure, and function after damage, and involves complex bio-physiological mechanisms including cell differentiation and immune responses. We constructed four regenerative protein-protein interaction (PPI) networks using dynamic models and AIC (Akaike’s Information Criterion), based on time-course microarray data from the regeneration of four zebrafish organs: heart, cerebellum, fin, and retina. We extracted core and organ-specific proteins, and proposed a recalled-blastema-like formation model to uncover regeneration strategies in zebrafish.

Results

It was observed that the core proteins were involved in TGF-β signaling for each step in the recalled-blastema-like formation model and TGF-β signaling may be vital for regeneration. Integrins, FGF, and PDGF accelerate hemostasis during heart injury, while Bdnf shields retinal neurons from secondary damage and augments survival during the injury response. Wnt signaling mediates the growth and differentiation of cerebellum and fin neural stem cells, potentially providing a signal to trigger differentiation.

Conclusion

Through our analysis of all four zebrafish regenerative PPI networks, we provide insights that uncover the underlying strategies of zebrafish organ regeneration.

     

Effects of Copper,Nickel, and Sulfate from the Smelters at Sudbury,Ontario (Canada) on Microbial Communities in Lakes

Analysis of water and sediments from deep and shallow environments in lakes located 6–154 km east or southeast of the smelters at Sudbury, Ontario (Canada) revealed variable, interactive effects of copper, nickel, and sulfate from smelter fallout on lacustrine microfloras. Metal species in sediments were differentiated by sequential extractions, and the nature, abundances, and activities of microbial populations were represented by chlorophyll-a in water and by CO₂ production, fatty acids, phospholipids, dehydrogenase, alkaline phosphatase, and spectral properties of humic matter in sediments. Smelter fallout declined logarithmically with distance from the smelters, and its effects on microfloras depended on the type of microorganism or microbial process and on environmental factors and the abundances of metal species and detoxifying agents. Extractable copper and nickel had toxic effects, which were not attributable solely to the exchangeable fractions, but in certain cases nickel counteracted copper toxicity. Sedimentary sulfide as a whole or sulfide produced by bacterial sulfate reduction, or low oxidation–reduction potential regardless of sulfide concentration, ameliorated metal toxicity by making the metals less bioavailable; and toxicity showed a “quantum jump” when detoxifying agents fell below certain critical concentrations, implying the existence of threshold levels of bioavailable metals above which toxicity increased abruptly. In some cases metal toxicity was lowest in the lakes closest to the smelters (because sulfate concentrations were highest) as well as in the lakes furthest away, and was highest at intermediate distances. The results also suggest that nickel pollution led to ecological succession whereby nickel-tolerant microbial populations replaced nickel-sensitive ones.     

木槿与野西瓜苗花特征和繁育系统的比较研究

为比较分析柱头裂片运动的野西瓜苗和不运动的木槿在花特征和繁育系统上的差异,对其花性状、花粉/胚珠比和不同授粉处理的座果率进行了测定。结果表明:(1)木槿与野西瓜苗在花冠大小、花瓣长及底宽、花萼长与宽、雄蕊长、最上轮雄蕊高度、雄蕊柱长及其底径、花柱长度和雌雄异位间均存在十分显著的差异(P<0.01),但二者的最下轮雄蕊高度间无显著性差异(P>0.05)。(2)木槿的花粉/胚珠比为874.90±20.79,繁育系统属兼性异交类型;野西瓜苗的花粉/胚珠比为24.72±0.68,繁育系统属专性自交类型。(3)木槿自然套袋的座果率为0%,人工自交为2.04%,人工杂交为35.85%;野西瓜苗自动自交和人工自交的座果率均为100%,人工杂交为95.30%。木槿与野西瓜苗在花性状、花粉/胚珠比及花部行为等方面形成了与其繁育系统(兼性异交vs.专性自交)相适应的花特征。     

In vitro folding of methionine‐arginine human lyspro‐proinsulin S‐sulfonate—Disulfide formation pathways and factors controlling yield

We investigated the in vitro folding of an oxidized proinsulin (methionine‐arginine human lyspro‐proinsulin S‐sulfonate), using cysteine as a reducing agent at 5°C and high pH (10.5–11). Folding intermediates were detected and characterized by means of matrix‐assisted laser desorption ionization mass spectrometry (MALDI‐MS), reversed‐phase chromatography (RPC), size‐exclusion chromatography, and gel electrophoresis. The folding kinetics and yield depended on the protein and cysteine concentrations. RPC coupled with MALDI‐MS analyses indicated a sequential formation of intermediates with one, two, and three disulfide bonds. The MALDI‐MS analysis of Glu‐C digested, purified intermediates indicated that an intra‐A‐chain disulfide bond formed first among A6, A7, and A11. Various non‐native intra‐A (A20 with A6, A7, or A11), intra‐B (between B7 and B19), and inter‐A‐B disulfide bonds were observed in the intermediates with two disulfide bonds. The intermediates with three disulfide bonds had mainly the non‐native intra‐A and intra‐B bonds. At a cysteine‐to‐proinsulin‐SH ratio of 3.5, all intermediates with the non‐native disulfide bonds were converted to properly folded proinsulin via disulfide bond reshuffling, which was the slowest step. Aggregation via the formation of intermolecular disulfide bonds of early intermediates was the major cause of yield loss. At a higher cysteine‐to‐proinsulin‐SH ratio, some intermediates and folded MR‐KPB‐hPI were reduced to proteins with thiolate anions, which caused unfolding and even more yield loss than what resulted from aggregation of the early intermediates. Reducing protein concentration, while keeping an optimal cysteine‐to‐protein ratio, can improve folding yield significantly. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010     

Natural products as sources of new fungicides (IV): Synthesis and biological evaluation of isobutyrophenone analogs as potential inhibitors of class-II fructose-1,6-bisphosphate aldolase

Several recently identified antifungal compounds share the backbone structure of acetophenones. The aim of the present study was to develop new isobutyrophenone analogs as new antifungal agents. A series of new 2,4-dihydroxy-5-methyl isobutyrophenone derivatives were prepared and characterized by ¹H, ¹³C NMR and MS spectroscopic data. These products were evaluated for in vitro antifungal activities against seven plant fungal pathogens by the mycelial growth inhibitory rate assay. Compounds 3, 4a, 5a, 5b, 5e, 5f and 5g showed a broad-spectrum high antifungal activity. On the other hand, for the first time, these compounds were also assayed as potential inhibitors against Class II fructose-1,6-bisphosphate aldolase (Fba) from the rice blast fungus, Magnaporthe grisea. Compounds 5e and 5g were found to exhibit the inhibition constants (Ki) for 15.12 and 14.27?μM, respectively, as the strongest competitive inhibitors against Fba activity. The possible binding-modes of compounds 5e and 5g were further analyzed by molecular docking algorithms. The results strongly suggested that compound 5g could be a promising lead for the discovery of new fungicides via targeting Class II Fba.     

蛇床子素通过促进胃癌细胞N87凋亡和细胞周期阻滞而抑制细胞增殖

蛇床子素是从伞形科植物蛇床中提取的一类具有生物活性的化合物。研究显示,蛇床子素对多种肿瘤细胞具有抑制作用,然而尚未有研究揭示其对胃癌N87细胞的抗肿瘤活性。本文研究了蛇床子素在体外和荷瘤小鼠体内对胃癌N87细胞的抗肿瘤效应,并进一步利用流式细胞术、TUNEL试验及Western印迹检测分析其对细胞周期及细胞凋亡的影响,以探索其作用机制。研究结果表明,蛇床子素有效地抑制了体外培养的N87细胞生长,并呈浓度依赖效应。本文还建立了N87的荷瘤小鼠模型。结果显示,无论是在低剂量(50 mg/kg)或高剂量(100 mg/kg)情况下,蛇床子素均显示了有效的肿瘤生长抑制效果。流式细胞术及Western印迹的结果表明,蛇床子素诱导N87细胞阻滞在G_2/M期。通过流式细胞术、TUNEL测试及Western印迹结果证明,蛇床子素通过激活胱天蛋白酶-3依赖的凋亡通路,最终导致了N87细胞凋亡的发生。综上所述,本研究显示,蛇床子素在胃癌N87细胞中通过促进细胞凋亡而发挥其抗肿瘤活性,这将为其应用于胃癌的临床治疗提供理论参考。