Serum proteomic signature of human chagasic patients for the identification of novel potential protein biomarkers of disease

Chagas disease is initiated upon infection by Trypanosoma cruzi. Among the health consequences is a decline in heart function, and the pathophysiological mechanisms underlying this manifestation are not well understood. To explore the possible mechanisms, we employed IgY LC10 affinity chromatography in conjunction with ProteomeLab PF2D and two-dimensional gel electrophoresis to resolve the proteome signature of high and low abundance serum proteins in chagasic patients. MALDI-TOF MS/MS analysis yielded 80 and 14 differentially expressed proteins associated with cardiomyopathy of chagasic and other etiologies, respectively. The extent of oxidative stress-induced carbonyl modifications of the differentially expressed proteins (n = 26) was increased and coupled with a depression of antioxidant proteins. Functional annotation of the top networks developed by ingenuity pathway analysis of proteome database identified dysregulation of inflammation/acute phase response signaling and lipid metabolism relevant to production of prostaglandins and arachidonic acid in chagasic patients. Overlay of the major networks identified prothrombin and plasminogen at a nodal position with connectivity to proteome signature indicative of heart disease (i.e., thrombosis, angiogenesis, vasodilatation of blood vessels or the aorta, and increased permeability of blood vessel and endothelial tubes), and inflammatory responses (e.g., platelet aggregation, complement activation, and phagocyte activation and migration). The detection of cardiac proteins (myosin light chain 2 and myosin heavy chain 11) and increased levels of vinculin and plasminogen provided a comprehensive set of biomarkers of cardiac muscle injury and development of clinical Chagas disease in human patients. These results provide an impetus for biomarker validation in large cohorts of clinically characterized chagasic patients.     

青藏高原异地半圈养藏羚警戒行为的适应性研究

行为是反映动物应对环境变化的最直接形式。动物可以根据周围环境条件的变化以及自身的生理状况来调整行为,异地放养是保护珍稀动物的有效方法,但必然会对其行为产生影响。为了探讨藏羚(Pantholops hodgsonii)对异地环境的行为学适应,对异地圈养藏羚的警戒行为进行了不同季节间的比较研究,采用全事件记录法和焦点动物取样法,记录和统计了异地圈养藏羚在冷季和暖季的警戒行为,进而推测其对人类干扰的行为适应性。研究结果表明,雌性和雄性藏羚的警戒时间及警戒比例(警戒时间占全天活动时间的比例)在暖季存在显著差异(警戒时间:Z=4.36,P<0.05;警戒比例:Z=4.559,P<0.05),而在冷季则无差异(警戒时间:Z=0.001,P>0.05;警戒比例:Z=0.0014,P>0.05);而季节差异对雌、雄性藏羚的警戒时间、警戒比例均具有极显著的影响(雄性-警戒时间:F=31.758,P<0.01;警戒比例:F=21.768,P<0.01;雌性-警戒时间:F=14.98,P<0.01;警戒比例:F=11.05,P<0.01);但是季节和性别对藏羚警戒行为的影响没有交互作用(Z=?0.576,P>0.05)。这些结果提示异地圈养藏羚警戒行为的变化可能是对陌生环境适应的结果。     

Interleukin-4 Restores Insulin Sensitivity in Lipid-Induced Insulin-Resistant Adipocytes

Obesity and latent inflammation in adipose tissue significantly contribute to the development of insulin resistance (IR) and type 2 diabetes. Here we studied whether the antiinflammatory interleukin-4 (IL-4) can restore insulin sensitivity in cultured 3T3-L1 adipocytes. The activity of key components of the insulin signaling cascade was assessed by immunoblotting using phospho-specific antibodies to insulin receptor substrate IRS1 (Tyr612), Akt (Thr308 and Ser473), and AS160 (Ser318) protein that regulates translocation of the GLUT4 glucose transporter to the plasma membrane. IR was induced in mature adipocytes with albumin-conjugated palmitate. IR significantly reduced phosphorylation levels of all the above-mentioned proteins. Addition of IL-4 to the culturing medium during IR induction led to a dose-dependent stimulation of the insulin-promoted phosphorylation of IRS1, Akt, and AS160. At the optimal concentration of 50 ng/ml, IL-4 fully restored activation of the insulin cascade in IR cells, but it did not affect insulin signaling activation in the control cells. IL- 4 neither upregulated expression of key adipogenesis markers GLUT4 and PPARγ nor caused lipid accumulation in the adipocytes. These results demonstrate that IL-4 can restore insulin sensitivity in adipocytes via mechanisms not associated with induced adipogenesis or de novo formation of lipid depots.     

留学生全英文组织学教学实践与体会

留学生教育作为高等院校国际化程度的一个重要尺度,已经成为高等教育的重要任务之一。留学生教育质量的高低在留学生教育事业上有着举足轻重的地位。我们体会到,通过采取以下措施,可以提高留学生教学质量:加强师资队伍建设,提高授课教师专业素质;多种教学模式,提高学生学习兴趣;加强师生交流,提高学习热情。     

Identification of proteins overexpressed in papillary thyroid tumors

A modified method of proteome comparative analysis based on preliminary removal of cell structural proteins by extraction using salt buffer and subsequent separation of extracts by two-dimensional gel electrophoresis was developed. Identification of differentially expressed proteins by mass spectrometry has revealed three proteins with noticeably increased level of synthesis in most samples of papillary thyroid tumors compared to normal tissues. An increase in ubiquitin content was found for the first time. Oncomarker search efficiencies by two-dimensional gel electrophoresis and bioinformatic search were compared.     

人脐血间充质干细胞分离培养方法的优化

目的探讨人脐血间充质干细胞（MSCs）体外培养纯化的最佳方法,为脐血MSCs在临床的广泛应用奠定基础。方法无菌条件下采集足月分娩和早产儿脐血,密度梯度离心法分离脐血单个核细胞,比较胎龄、不同培养基、接种密度、首次换液时间对脐血MSCs原代培养过程的影响,通过免疫荧光方法检测表面标记物的表达情况,观察脐血MSCs的生物学特性。结果足月分娩脐血,采用MesencultTM培养基,以5×106/cm2的密度接种,首次换液时间为7d时,脐血MSCs原代培养成功率较高。相同培养条件下,早产儿脐血培养成功率高于足月分娩脐血。人脐血MSCs强表达CD29、CD44和CD90,不表达造血干细胞表面标志CD34。结论优化筛选到一种合适的人脐血MSCs培养纯化条件。     

微卫星座位对实验动物beagle犬的遗传分析

目的对美国进口、广州自养beagle犬基因组中存在的微卫星结构进行分析,研究其群体的微卫星多态性,以此探索在分子水平上对作为实验动物的beagle犬进行检测。方法通过微卫星分子标记技术进行遗传背景分析,并结合微卫星位点测序结果,研究DNA分子特征。结果在研究位点上共发现6个复等位基因,进口犬群体共有6个等位基因片段,自养犬群体共有5个等位基因片段,根据基因型计算各群体等位基因频率,由相关公式计算杂合度、群体多态信息含量(PIC)、基因纯合率、基因分化系数。结论两群体的杂合度、PIC值均较高(分别为0.7010、0.6747和0.7876、0.7515),基因分化系数很低(0.021),表明两群体没有形成明显的独立群。     

Differential role of microenvironment in microencapsulation for improved cell tolerance to stress

The effect of the microenvironment in alginate–chitosan–alginate (ACA) microcapsules with liquid core (LCM) and solid core (SCM) on the physiology and stress tolerance of Sacchromyces cerevisiae was studied. The suspended cells were used as control. Cells cultured in liquid core microcapsules showed a nearly twofold increase in the intracellular glycerol content, trehalose content, and the superoxide dismutase (SOD) activity, which are stress tolerance substances, while SCM did not cause the significant physiological variation. In accordance with the physiological modification after being challenged with osmotic stress (NaCl), oxidative stress (H₂O₂), ethanol stress, and heat shock stress, the cell survival in LCM was increased. However, SCM can only protect the cells from damaging under ethanol stress. Cells released from LCM were more resistant to hyperosmotic stress, oxidative stress, and heat shock stress than cells liberated from SCM. Based on reasonable analysis, a method was established to estimate the effect of microenvironment of LCM and SCM on the protection of cells against stress factors. It was found that the resistance of LCM to hyperosmotic stress, oxidative stress, and heat shock stress mainly depend on the domestication effect of LCM’s microenvironment. The physical barrier of LCM constituted by alginate–chitosan membrane and liquid alginate matrix separated the cells from the damage of oxidative stress and ethanol stress. The significant tolerance against ethanol stress of SCM attributed to the physical barrier consists of solid alginate–calcium matrix and alginate–chitosan membrane.     

Rho-associated kinase (ROCK) inhibition reverses low cell activity on hydrophobic surfaces

Hydrophobic polymers do not offer an adequate scaffold surface for cells to attach, migrate, proliferate, and differentiate. Thus, hydrophobic scaffolds for tissue engineering have traditionally been physicochemically modified to enhance cellular activity. However, modifying the surface by chemical or physical treatment requires supplementary engineering procedures. In the present study, regulation of a cell signal transduction pathway reversed the low cellular activity on a hydrophobic surface without surface modification. Inhibition of Rho-associated kinase (ROCK) by Y-27632 markedly enhanced adhesion, migration, and proliferation of osteoblastic cells cultured on a hydrophobic polystyrene surface. ROCK inhibition regulated cell-cycle-related molecules on the hydrophobic surface. This inhibition also decreased expression of the inhibitors of cyclin-dependent kinases such as p21^cip1 and p27^kip1 and increased expression of cyclin A and D. These results indicate that defective cellular activity on the hydrophobic surface can be reversed by the control of a cell signal transduction pathway without physicochemical surface modification.     

2008年度国家自然科学基金委员会微生物学学科项目申请与资助情况分析

2008年度,国家自然科学基金项目申请实行了新的“申请代码”,使其能够体现科学基金不断适应变化了的基础研究状况,同时也体现基金资助项目更加侧重基础、更加侧重前沿的思想。本文对申请代码的修订、2008年度微生物学学科申请与资助项目情况进行了总结和分析,希望能为科研人员在2009年及今后申请国家自然科学基金项目时提供参考。