P53和P21在PC12细胞分化中的作用

目的探讨P53及其下游P21蛋白在PC12细胞分化中的可能作用机制。方法用反转录病毒质粒pBabe-P53/m175转染未分化PC12细胞,经筛选后建立野生型P53蛋白功能丧失的细胞系PC12(P53/m175);利用倒置相差显微镜、流式细胞术及Western blot等方法,比较两种细胞在神经生长因子(NGF)作用后,细胞分化表型、细胞周期及相关蛋白表达的改变。结果NGF作用于正常PC12细胞组,P53/P21蛋白表达持续升高,细胞G1期阻滞出现的时间与蛋白表达开始增加的时间相一致;而在NGF作用的PC12(P53/m175)细胞组,细胞不能表达P21蛋白,且细胞周期G1期阻滞的程度也出现显著下降。NGF作用下,两组细胞都能观察到神经突起的生长,表现出明显的分化表型。结论PC12细胞经NGF作用后出现P53及P21蛋白持续表达增加,主要介导了细胞分化过程中细胞周期G1期阻滞这一特征的出现,但并不是导致神经突起进行性生长这一特征的必需条件。     

Comparison between in vitro properties of washed platelet concentrates suspended in M-sol and those in BRS-A,both of which were prepared with an automated cell processor

Background

Washed platelet concentrate (WPC) is prepared manually in general, but automated preparation is desirable to minimize variation in the WPC quality and enhance WPC production. Recently, the software was improved for an automated cell processor (ACP) to control all processes of WPC preparation. M-sol and BRS-A, which are mixtures of medical solutions, are widely used for WPC preparation with a manual method in Japan. In this study, we prepared WPC suspended in M-sol (WPC-M) or BRS-A (WPC-B) with the ACP, and compared their in vitro properties during 7-day storage.

电针对心肌缺血大鼠下丘脑内单胺类递质含量的影响

目的：探讨电针治疗心肌缺血的作用机制。方法：从80只健康SD大鼠中随机选择10只作为正常对照组,其余大鼠结扎冠状动脉旋前降支复制心肌缺血动物模型。选取模型复制成功的大鼠随机分为模型组、“神门”穴组、“内关”穴组和“太渊”穴组,每组10只。分别电针大鼠左侧“神门”穴、“内关”穴和“太渊”穴,每次刺激10min,每目1次,连续3d。采用酶联免疫吸附试验测定下丘脑室旁核区去甲肾上腺素（norepinephrine,NE）、多巴胺（dopamine,DA）、5-羟色胺（5-hydroxytryptamine,5-HT）含量。结果：模型组大鼠下丘脑室旁核区NE、DA和5-HT含量均显著下降（P〈0．01）。与模型组比较,“内关”组和“神门”组NE、DA、5-HT含量均显著升高（P〈0．01）;“太渊”组仅NE含量显著升高（P〈0．05）。结论：电针“神门”、“内关”穴治疗心肌缺血的机制与其促进下丘脑室旁核区单胺类递质的释放有关。     

溶血磷脂酸诱导PC12细胞凋亡的机制研究

目的 探究溶血磷脂酸诱导PC12细胞凋亡的机制并提出干预措施。方法 实验1:不同浓度LPA(0 μM 、10 μM、20 μM、40 μM)处理PC12细胞24 h; 实验2:LPA(40 μM)分别处理PC12细胞不同时间(0 h、6 h、12 h、24 h); 实验3:正常组(0 μM LPA)、LPA组(40 μM LPA)和干预组(5 μM SP600125预处理2 h+40 μM LPA)培养24 h; CCK-8检测细胞活力; TUNEL染色检测细胞凋亡比例; WesternBlot检测Bcl2、caspase 3、磷酸化JNK水平。结果 LPA以时间依赖和浓度依赖的方式使PC12细胞的细胞活力和Bcl2水平降低,而使PC12细胞的凋亡指数和caspase 3水平增高; SP600125(5 μM)预处理不仅明显阻断LPA诱导的PC12细胞活力下降、细胞凋亡,并且极大地抑制了LPA诱导的JNK通路的激活、Bcl2水平的下调和caspase 3水平的上调。结论 JNK特异性抑制剂SP600125预处理能够明显阻断LPA诱导的PC12细胞损伤。     

Intercellular communication via gap junctions in activated rat hepatic stellate cells

BACKGROUND AND AIMS: Gap junctional communication was studied in quiescent and activated hepatic stellate cells. METHODS: Connexin expression and intercellular dye transfer were studied in rat hepatic stellate cells in culture and in vivo. RESULTS: Protein expression of connexin 43 was up-regulated in activated hepatic stellate cells in vivo and in vitro and was mainly localized on the cell surface, whereas connexin 26 was found intracellularly. In contrast to hepatocytes, hepatic stellate cells do not express connexin 32. Confluent hepatic stellate cells in culture communicate via gap junctions, resulting in lucifer yellow transfer and propagation of intracellular calcium signals. Phorbol ester induces a protein kinase C-dependent hyperphosphorylation and degradation of connexin 43 and inhibits intercellular communication on a short-term time scale. At the long-term level, vitamin D(3) , lipopolysaccharide, thyroid hormone T(3), dexamethasone, platelet-derived growth factor, endothelin 1, and interleukin 1beta up-regulate connexin 43 protein and messenger RNA expression and enhance intercellular communication. Slight down-regulation of connexin 43 is observed in response to vitamin A. Connexin 43 induction by endothelin 1 is inhibited by both endothelin A and endothelin B receptor antagonists. In coculture systems, hepatic stellate cells communicate with each other, which is suggestive of a syncytial organization, but no communication was found between hepatic stellate cells and other liver cell types. As shown by immunohistochemistry and electron microscopy, gap junctions are formed between activated hepatic stellate cells in vivo. CONCLUSIONS: Gap junctional communication occurs between hepatic stellate cells, is enhanced after activation, and underlies complex regulation by cytokines, hormones, and vitamins.     

Is mitochondrial DNA copy number a good prognostic marker in resectable pancreatic cancer?

Background

The aim of this prospective study was to investigate mitochondrial DNA (mtDNA) copy number in a group of resectable pancreatic cancer (PC) tumor tissues and adjacent normal pancreatic tissues, and to explore the correlation between the mtDNA content in tissues and the clinicopathological parameters and the overall survival.

miRNA-21减轻氧糖剥夺对PC12细胞的损伤

目的:探讨微小RNA(miRNA)-21对低氧缺血损伤PC12细胞的影响。方法:体外培养PC12细胞,建立氧糖剥夺(OGD)损伤模型。细胞随机分为对照组、OGD组、阴性对照序列+OGD组、miRNA-21 inhibitor+OGD组和miRNA-21 mimic+OGD组。通过采用CCK-8、real-time PCR、Western blot等技术探讨miRNA-21对OGD损伤PC12细胞的影响和机制。结果:降低miRNA-21的表达,受OGD损伤的PC12细胞活力明显下降;增加miRNA-21的表达,受OGD损伤的PC12细胞活力明显增加。进一步发现miRNA-21促进OGD损伤PC12细胞的AKT磷酸化。结论:miRNA-21明显增加OGD损伤PC12细胞的活力,其机制可能与激活PI3K/AKT信号通路有关。     

RNA干扰抑制Nogo-A基因表达对PC12细胞多巴胺释放的影响

目的 研究Nogo-A基因沉默对PC12细胞多巴胺释放的影响.方法 构建靶向Nogo-A的短发夹样RNA(shRNA)真核表达载体,并经脂质体转染PC12细胞,以逆转录聚合酶链反应(RT-PCR)和免疫印迹法检测对Nogo-A mRNA及蛋白的抑制效应.采用高效液相色谱仪(HPLC)检测转染前后多巴胺释放的变化.结果 将重组质粒转染到PC12细胞48h后,Nogo-A基因表达明显受抑、多巴胺释放量减少.结论 Nogo-A可能参与PC12细胞多巴胺的释放.     

Effectiveness of washed platelet concentrate and red cell transfusions for a patient with anhaptoglobinemia with antihaptoglobin antibody

A 71-year-old Japanese male with myelodysplastic syndrome progressing to overt leukaemia and hepatocellular carcinoma developed dyspnea and urticaria immediately after infusion of platelet concentrate (PC). He exhibited an identical reaction following blood transfusion. Serum haptoglobin was undetectable. The patient was determined to be homozygous for Hp(del) by polymerase chain reaction (PCR). Antibody to haptoglobin was detected by enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. No antibodies against human leucocyte antigen (HLA) or platelet-specific antigens were detected. Washed PC and washed red blood cells were effective in preventing the transfusion-related anaphylactoid reactions.