△LuxS的表型分析及其在GBS毒力调控机制研究中的应用

目的采用LuxS缺失突变株模型对B型链球菌中数量感应相关分子LuxS的功能及与其相关的自诱导因子-2数量感应通路进行研究，以探索其毒力调控机制。方法采用RT-PCR法、菌落印迹分析、生长曲线测定、cAMP因子测定等方法对该缺失突变菌株的表型特性进行了研究。最后应用哈氏弧菌作为报告菌株，通过生物发光测定法分析了突变株对B型链球菌诱导报告菌株中的生物发光活性的影响。结果发现此缺失突变可导致B型链球菌中scpB基因表达的上调；与野生株相比，突变株的生物发光诱导活性比野生株降低了大约两倍。结论本研究结果证实了LuxS在GBS中AI-2数量感应通路中的重要性，并为GBS中毒力调控机制的进一步研究提供了新的线索。     

褪黑素对子宫内膜异位症大鼠细胞凋亡相关蛋白的影响

目的观察褪黑素(MT)对大鼠子宫内膜异位症(EM)模型细胞凋亡调控相关蛋白的影响。方法采用手术移植法制备大鼠EM模型,大鼠随机分为正常对照组、模型对照组和MT高、低剂量组,免疫组织化学法检测异位内膜Bcl-2、Fas、细胞间粘附分子(ICAM)-1的表达,同时检测脾脏自然杀伤(NK)细胞活性。结果MT治疗组与模型组比较异位内膜Bcl-2、ICAM-1表达明显下降,Fas表达明显升高,脾脏NK细胞活性显著增加。结论MT具有抑制异位内膜Bcl-2、ICAM-1表达以及增强Fas表达和脾脏NK细胞活性的作用。     

An analysis of astrocytic cell lines with different abilities to promote axon growth

The adult mammalian central nervous system (CNS) lacks the capacity to support axonal regeneration. There is increasing evidence to suggest that astrocytes, the major glial population in the CNS, may possess both axon-growth promoting and axon-growth inhibitory properties and the latter may contribute to the poor regenerative capacity of the CNS. In order to examine the molecular differences between axon-growth permissive and axon-growth inhibitory astrocytes, a panel of astrocyte cell lines exhibiting a range of axon-growth promoting properties was generated and analysed. No clear correlation was found between the axon-growth promoting properties of these astrocyte cell lines with: (i) the expression of known neurite-outgrowth promoting molecules such as laminin, fibronectin andN-cadherin; (ii) the expression of known inhibitory molecules such tenascin and chondroitin sulphate proteoglycan; (iii) plasminogen activator and plasminogen activator inhibitor activity; and (iv) growth cone collapsing activity. EM studies on aggregates formed from astrocyte cell lines, however, revealed the presence of an abundance of extracellular matrix material associated with the more inhibitory astrocyte cell lines. When matrix deposited by astrocyte cell lines was assessed for axon-growth promoting activity, matrix from permissive lines was found to be a good substrate, whereas matrix from the inhibitory astrocyte lines was a poor substrate for neuritic growth. Our findings, taken together, suggest that the functional differences between the permissive and the inhibitory astrocyte cell lines reside largely with the ECM.     

The human major histocompatibility complex class Ib molecule HLA-E binds signal sequence-derived peptides with primary anchor residues at positions 2 and 9

Human histocompatibility leukocyte antigen E (HLA-E) and mouse major histocompatibility complex (MHC) class Ib antigen, Qa-1, share the same substitutions at two normally conserved positions 143 and 147, which are likely to affect binding of the C terminus of peptides. Qa-1 is able to bind a peptide derived from the leader sequence of H-2 D and H-2 L molecules. We developed a peptide binding assay in vitro to compare the binding specificity of HLA-E with the mouse MHC class Ib molecule Qa-1. We demonstrate that HLA-E binds, although poorly, the peptide which binds to Qa-1 and that it also binds nonamer signal sequence-derived peptides from human MHC class I molecules. Using alanine and glycine substitutions, we could define primary anchor residues at positions 2 and 9 and secondary anchor residues at position 7 and possibly 3.     

60Co辐照血红细胞CR1分子数目的变化

目的研究不同剂量60Co γ射线辐照全血在保存期内红细胞CR1分子数目的变化.方法应用酶联法定量测定经15～35GY五个照射剂量辐照全血在保存期内红细胞CR1分子数目.结果照射后1d,15～25GY剂量组红细胞CR1分子数目相互间比较及分别与对照组比较无明显差异(P＞0.05);经30、35GY辐照红细胞CR1分子数目分别与其他剂量组和对照组比较有明显差异(P＜0.05～0.01).另外,随着保存期的延长,各剂量组和对照组红细胞CR1分子数目呈阶梯式下降,尤其在照射后3d,30和35GY剂量组红细胞CR1分子数目接近于照射后7d水平,二者相互比较无明显差异(P＞0.05).结论在一定范围内(15～25GY)60Co γ射线剂量辐照对红细胞CR1分子数目无明显影响.     

Rosiglitazone down-regulates lipopolysaccharide-induced expression of CD40 and intercellular adhesion molecule 1 in rat peritoneal mesothelial cells through a NF-κB dependent mechanism

Objective To investigate the effect and mechanism by which PPARγ ligand, rosiglitasone, regulates the expression of CD40 and intercellular adhesion molecule 1 (ICAM-1) in the rat peritoneal mesothelial cells (RPMCs) induced by lipopolysaccharide (LPS). Methods RPMCs were harvested from Sprague-Dawley rat peritoneal cavity and maintained under defined in vitro conditions. The cells were randomly divided into groups as follows: medium, LPS (5 mg/L), LPS (5 mg/L)+BAY11-7085(5 μmol/L, NF-κB inhibitor), rosiglitazone (10 μmol/L or 20 μmol/L, peroxisome proliferator-activated receptor γ activator), LPS (5 mg/L)+rosiglitazone (10 μmol/L)+GW9662 (3 μmol/L, peroxisome proliferator-aetivatcd receptor γ antagonist), and LPS (5 mg/L)+vehicle (DMSO 0.2 ml/L). The expressions of CD40 and ICAM-1 RNA in RPMCs were examined by RT-PCR after 3 hour treatment, and the protein expressions of CD40, ICAM-1, p-NF-κB p65 and p-IκBα were examined by Western blot or immunofluorescence after 24 hour treatment. Results Following treatment with LPS, both the expressions of CD40 and ICAM-1 protein in RPMCs were up-regulated significantly (P<0.05), and the phosphoralation of p65 was increased greatly (1.10±0.17 vs 0.55±0.06, P<0.05). BAY11-7085 (5 μmol/L) significantly decreased the protein expression of p-p65 (0.22±0.11 vs 1.10±0.17, P<0.01), CD40 (0.34±0.02 vs 0.50±0.06, P<0.05) and ICAM-1 (0.35±0.16 vs 0.74±0.03, P<0.05). Pretreated with rosiglitazone for 3 h then added with LPS for 1 h, the levels of p-p65, CD40 and ICAM-1 in RPMCs were significantly decreased compared with those of LPS group (0.77±0.08 vs 0.90±0.10, P相似文献   

Elevation of cell adhesion molecule immunoreactivity in the anterior cingulate cortex in bipolar disorder.

BACKGROUND: Neuroimaging reports of increases in signal hyperintensities in white and deep gray matter and other work indicate that there might be an inflammatory response in affective disorders. METHODS: The microvascular immunoreactivity of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 was measured with image analysis in postmortem tissue from the anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (DLPFC) from 15 unipolar and 15 bipolar subjects and compared with each other and with 15 subjects with schizophrenia and 15 control subjects. RESULTS: Intercellular adhesion molecule-1 immunoreactivity in gray and white matter of the ACC in bipolar subjects was increased compared with control subjects (gray: p =.001; white: p <.001) and schizophrenic subjects (gray: p =.016; white: p =.025) and modestly increased in white matter compared with unipolar subjects (p =.049). No such differences were found in the DLPFC. CONCLUSIONS: These findings are consistent with the presence of an inflammatory response in the ACC in bipolar disorder.