Dopamine receptor-interacting protein 78 acts as a molecular chaperone for CCR5 chemokine receptor signaling complex organization

Chemokine receptors are members of the G protein-coupled receptor (GPCR) family. CCR5 and CXCR4 act as co-receptors for human immunodeficiency virus (HIV) and several efforts have been made to develop ligands to inhibit HIV infection by blocking those receptors. Removal of chemokine receptors from the cell surface using polymorphisms or other means confers some levels of immunity against HIV infection. Up to now, very limited success has been obtained using ligand therapies so we explored potential avenues to regulate chemokine receptor expression at the plasma membrane. We identified a molecular chaperone, DRiP78, that interacts with both CXCR4 and CCR5, but not the heterodimer formed by these receptors. We further characterized the effects of DRiP78 on CCR5 function. We show that the molecular chaperone inhibits CCR5 localization to the plasma membrane. We identified the interaction region on the receptor, the F(x)6LL motif, and show that upon mutation of this motif the chaperone cannot interact with the receptor. We also show that DRiP78 is involved in the assembly of CCR5 chemokine signaling complex as a homodimer, as well as with the Gαi protein. Finally, modulation of DRiP78 levels will affect receptor functions, such as cell migration in cells that endogenously express CCR5. Our results demonstrate that modulation of the functions of a chaperone can affect signal transduction at the cell surface.     

覆盆子抗耐药真菌活性成分提取方法比较及活性部位初步筛选

目的 考察热回流法、超声法及冷浸法提取覆盆子抗菌活性成分的优劣,初步筛选覆盆子提取物中具有体外抗真菌活性的部位.方法 以覆盆子提取物联合氟康唑体外抗耐药真菌活性为主要指标,结合提取率评价三种提取覆盆子抗菌活性成分方法的优劣;依次用石油醚、氯仿、乙酸乙酯及正丁醇萃取覆盆子提取物,以所得部位联合氟康唑体外抗耐药真菌的活性为评价指标,初步筛选覆盆子提取物的抗菌活性部位.结果 热回流法、超声法及冷浸法三种提取方法的提取率分别为21.0％、16.8％及12.8％,所得提取物联合氟康唑对耐药菌株100的FICI值分别为0.035 2、0.032 2及0.046 9,所得提取物联合氟康唑对耐药菌株103的FICI值分别为0.033 2、0.031 7及0.039 1;覆盆子提取物的石油醚、氯仿、乙酸乙酯、正丁醇及水部位对耐药菌株100的FICI值分别为＞1、0.502 0、0.507 8、0.033 2及＞1,对耐药菌株103的FICI值分别为＞1、0.531 3、0.507 8、0.033 2及＞1.结论 与热回流法及冷浸法相比,超声法提取覆盆子抗菌活性成分简便、稳定、高效,是一种较优的提取方法;覆盆子提取物的活性部位为其正丁醇部位.     

鼠疫耶尔森菌毒力蛋白YopE新功能的初步研究

鼠疫耶尔森菌外部蛋白E（YopE）是鼠疫耶尔森菌的6种分泌蛋白之一,主要通过其144位的”精氨酸手指”结构与细胞膜耦联蛋白RhoGTP酶相互作用发挥功能.本文构建YopE及其144位突变体YopE(R144A)的可诱导表达系统,并优化了诱导条件. 用该系统结合流式细胞技术检测YopE和YopE(R144A)对细胞凋亡、细胞周期和细胞活性氧(ROS)水平的影响.结果显示：YopE(R144A)促进HeLa细胞凋亡|使G0/G1期细胞比例上升,G2/M期细胞比例下降;随着YopE(R144A)表达量增加,p21蛋白的表达量也增加| YopE(R144A)也能抑制细胞ROS的产生.研究结果提示,YopE在细胞内可能存在新的致病靶点.     

The First Case of Phaeohyphomycosis Caused by Rhinocladiella basitona in an Immunocompetent Child in China

We present the first case of phaeohyphomycosis caused by Rhinocladiella basitona (R. basitona) in China and describe the mycological characteristics of this pathogen. A 11-year-old girl was presented with plaque on her face for 3 years. Diagnosis was based on histopathology, mycology, and molecular identification. The patient was treated with terbinafine and itraconazole. This case is the second of phaeohyphomycosis caused by R. basitona in the world (previously belonging to Geniculosporium).     

Lovastatin enhances clearance of apoptotic cells (efferocytosis) with implications for chronic obstructive pulmonary disease

Statins are potent, cholesterol-lowering agents with newly appreciated, broad anti-inflammatory properties, largely based upon their ability to block the prenylation of Rho GTPases, including RhoA. Because phagocytosis of apoptotic cells (efferocytosis) is a pivotal regulator of inflammation, which is inhibited by RhoA, we sought to determine whether statins enhanced efferocytosis. The effect of lovastatin on efferocytosis was investigated in primary human macrophages, in the murine lung, and in human alveolar macrophages taken from patients with chronic obstructive pulmonary disease. In this study, we show that lovastatin increased efferocytosis in vitro in an 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase-dependent manner. Lovastatin acted by inhibiting both geranylgeranylation and farnesylation, and not by altering expression of key uptake receptors or by increasing binding of apoptotic cells to phagocytes. Lovastatin appeared to exert its positive effect on efferocytosis by inhibiting RhoA, because it 1) decreased membrane localization of RhoA, to a greater extent than Rac-1, and 2) prevented impaired efferocytosis by lysophosphatidic acid, a potent inducer of RhoA. Finally, lovastatin increased efferocytosis in the naive murine lung and ex vivo in chronic obstructive pulmonary disease alveolar macrophages in an HMG-CoA reductase-dependent manner. These findings indicate that statins enhance efferocytosis in vitro and in vivo, and suggest that they may play an important therapeutic role in diseases where efferocytosis is impaired and inflammation is dysregulated.     

Na+/H+ Exchanger Regulatory Factor-1 Is Involved in Chemokine Receptor Homodimer CCR5 Internalization and Signal Transduction but Does Not Affect CXCR4 Homodimer or CXCR4-CCR5 Heterodimer

Chemokine receptors are members of the G protein-coupled receptor (GPCR) family. CCR5 is also the principal co-receptor for macrophage-tropic strains of human immunodeficiency virus, type 1 (HIV-1), and efforts have been made to develop ligands to inhibit HIV-1 infection by promoting CCR5 receptor endocytosis. Given the nature of GPCRs and their propensity to form oligomers, one can consider ligand-based therapies as unselective in terms of the oligomeric composition of complexes. For example, a ligand targeting a CCR5 homomer could likely induce signal transduction on a heteromeric CCR5-CXCR4. Other avenues could therefore be explored. We identified a receptor adaptor interacting specifically with one receptor complex but not others. NHERF1, an adaptor known for its role in desensitization, internalization, and regulation of the ERK signaling cascade for several GPCRs, interacts via its PDZ2 domain with the CCR5 homodimer but not with the CXCR4-CCR5 heterodimer or CXCR4 homodimer. To further characterize this interaction, we also show that NHERF1 increases the CCR5 recruitment of arrestin2 following stimulation. NHERF1 is also involved in CCR5 internalization, as we demonstrate that co-expression of constructs bearing the PDZ2 domain can block CCR5 internalization. We also show that NHERF1 potentiates RANTES (regulated on activation normal T cell expressed and secreted)-induced ERK1/2 phosphorylation via CCR5 activation and that this activation requires NHERF1 but not arrestin2. Taken together, our results suggest that oligomeric receptor complexes can associate specifically with partners and that in this case NHERF1 could represent an interesting new target for the regulation of CCR5 internalization and potentially HIV infection.     

两种拟隐脉叶蝉的种群动态及生物学特性初步观察

拟隐脉叶蝉原产于东南亚及我国华南地区 ,近年传入美国并在夏威夷等地暴发成灾。为了从拟隐脉叶蝉的原产地寻找有效天敌 ,以便在传入地开展生物防治 ,作者近年在福建省福州地区对 2种拟隐脉叶蝉的种群动态及生物学特性进行调查。结果获知 :在福州地区的番石榴和相思树上 ,淡色拟隐脉叶蝉和叉线拟隐脉叶蝉年可发生 3～ 4代 ,若虫 5龄 ,夏秋冬初世代重叠 ,没有明显的越冬现象。它们的共同寄主有 :番石榴、甘薯、花生和扁豆。罩养条件下 ,淡色拟隐脉叶蝉也能在相思树上取食并产卵。     

扁柏属的核型及柏本亚科的细胞分类学研究

分析了美国扁柏、日本扁柏和日本花柏的核型,它们的核型公式分别为Ｋ（２ｎ）＝２２＝２２ｍ,２０ｍ＋２ｓｍ和１４ｍ＋８ｓｍ。作者比较了扁柏属６个代表种的核型,发现北美种类有比东亚种类原始的趋势。在柏本亚科中,扁柏属可能最进化,柏木属最原始,福建柏属和杂交属×Ｃｕｐｒｅｓｓｏｃｙｐｅｒｉｓ居中。论文还讨论了柏木和福建柏的系统位置。     

济南泉溪藻类及水质评价

调查了济南城内著名的黑虎泉、趵突泉、珍珠泉和五龙潭泉四大泉群中的藻类植物, 共计有80 种及变种, 分属于蓝、红、硅、裸、绿和轮藻门, 其中, 以硅藻门种类最丰富, 相对数量也占优势。根据藻类植物的分布, 利用指示生物法对泉水水质进行了定性初步评价, 结果表明, 济南的泉水较清洁。但是泉水涌出后的保洁和管理问题仍然较大, 需要重视。     

转人α-乳清白蛋白基因烟草中半胱氨酸含量的提高

将人α-乳清白蛋白基因构建到植物表达载体上,通过农杆菌介导采用叶盘法将人α-乳清白蛋白基因导入到烟草中,经过PCR和Southern blot分析表明:人α-乳清白蛋白基凶已经整合到烟草基因组中;经过RT-PCR葙GUS组织化学染色证明:人α-乳清白蛋白基因得到了表达.测定了9株转基因烟草叶片半胱氨酸含量,大部分植株有着明显的提高,最高幅度达到了318.02%,半胱氨酸含量平均提高了166.40%.