水通道蛋白5对PMA诱导的原代小鼠气道上皮细胞MUC5AC合成的影响

 目的 探讨水通道蛋白5(aquaporin 5,AQP5)对卟啉醇肉豆蔻酸乙酸酯(phorbol myristate acetate,PMA)诱导的原代培养小鼠气道上皮细胞MUC5AC合成的影响及可能机制。方法 原代培养两种小鼠(AQP5基因敲除鼠和野生鼠)气道上皮细胞,Transwell建立气液平面,2周后扫描电镜及角蛋白免疫组化鉴定气道上皮细胞。蛋白激酶(protein kinase C,PKC)特异性激动剂PMA刺激原代小鼠气道上皮细胞及PKC通路特异性阻断剂Calphostinc阻断该通路,ELISA检测两组小鼠MUC5AC蛋白水平的变化,用Western blot检测小鼠气道上皮细胞PMA刺激后PKC、p-PKC、p-p38、p38、ERK、p-ERK的表达差异。结果 气液平面培养后,扫描电镜显示培养的细胞上皮有微绒毛和纤毛覆盖,细胞角蛋白14免疫组化染色为阳性。PMA 20ng/mL 刺激24h后,两组小鼠气道上皮细胞分泌的MUC5AC明显升高,AQP5基因敲除鼠增加更显著(P<0.05),两者差异有统计学意义。PKC特异性阻断剂Calphostinc能阻断PMA引起的两组小鼠MUC5AC分泌。原代小鼠气道上皮细胞经PMA刺激后,Western blot检测显示PKC、p38磷酸化激活,ERK通路无变化。结论 AQP5通过PKC-p38信号通路影响黏蛋白MUC5AC的合成和分泌。     

佛波酯对人外周血DNT细胞表面抗原检测的影响及检测方法的探讨

目的探讨佛波酯（PMA）对人外周血淋巴细胞中TCRαβ＋CD4-CD8-T细胞（DNT细胞）表面抗原检测的影响及检测方法的探讨。方法分离人外周血单个核细胞,分别在激活前后对细胞进行TCRαβ、CD4和CD8荧光单抗标记,流式细胞术计数DNT细胞。结果 A方法（先激活,再标记）,淋巴细胞表面抗原CD4分子显著下调,DNT细胞与TCRαβ＋CD4＋CD8＋T细胞、TCRαβ-CD4-CD8-T细胞和TCRαβ-CD4＋CD8＋T细胞间无法设门,与正常对照比较,DNT细胞计数显著增加;B方法（先标记,再激活）,DNT细胞与其他细胞群设门清晰,与正常对照比较,对DNT细胞计数无明显影响;C方法（先标记,再联合激活）,DNT细胞检测结果与B方法相同。结论采用A方法（常规方法）,不能对活化后的DNT细胞进行准确计数;采用B和C方法（改进方法）,可以对活化后的DNT细胞进行准确计数,避免了磁珠或（和）流式分选,为其计数和表面抗原检测提供了一种新的简便方法。     

A role for the MAPK/ERK pathway in oligodendroglial differentiation in vitro: stage specific effects on cell branching

The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway is important for both long-term survival and timing of the progression of oligodendrocyte differentiation. Oligodendroglial cells treated with MEK inhibitor were distinguished by using stage specific markers: NG2 proteoglycan, A2B5, 2′3′nucleotide-cyclic 3′phosphodiesterase (CNPase) and myelin basic protein (MBP), and classified according to their morphology into different developmental stages. Treatment significantly increased the number of cells with more immature morphologies and decreased the number of mature cells. Furthermore, it increased the number of rounded cells that could not be classified into any of the oligodendroglial developmental stages. The strongest effects were usually observed shortly after treatment. Rounded cells were CNPase/MBP positive and they were not stained by anti-NG2 or A2B5, indicating that they were mature cells unable either to extend and/or to maintain their processes. These data showed an effect of the MAPK/ERK pathway on oligodendroglial branching, with possible consequences for the formation of the myelin sheath.     

Rottlerin inhibits human T cell responses

Rottlerin is a pharmacological inhibitor of protein kinase C (PKC) theta, a novel PKC selectively expressed in T lymphocytes. PKC theta is known to regulate T cell receptor (TCR)/CD28 signalling pathways in T lymphocytes, but the impact of PKC theta inhibition on human T cell responses remains undefined. In this work, we describe the effects of rottlerin on the responses of CD4+ and CD8+ human T lymphocytes upon polyclonal activation. We observed a dose-dependent inhibition of CD4+ and CD8+ T cell proliferation in response to anti-CD3/anti-CD28 antibodies stimulation in the presence of rottlerin. This inhibition was associated with impaired CD25 expression and decreased interleukin (IL)-2 production in activated T cells. In contrast, rottlerin did not alter IL-2-induced T cell proliferation. Furthermore, we demonstrated that rottlerin blocked interferon (IFN) gamma, IL-10 and IL-13 mRNA expression in TCR/CD28 activated CD4+ T cells. These findings place rottlerin as a potent immunosuppressive agent for the development of novel therapies in T cell mediated immune disorders.     

Rosmarinic acid down-regulates endothelial protein C receptor shedding in vitro and in vivo

The endothelial protein C receptor (EPCR) plays pivotal roles in coagulation and inflammation, however, its activity is markedly changed by ectodomain cleavage and release as the soluble protein (sEPCR). According to previous studies, there are approximately 100 ng/ml sEPCR in human plasma and the levels increase in inflammatory diseases. EPCR can be shed from the cell surface, and this is mediated by tumor necrosis factor-α converting enzyme (TACE). We recently reported on the anti-inflammatory and barrier protective activities of rosmarinic acid (RA), an important component of the leaves of Perilla frutescens. However, little is known about the effects of RA on EPCR shedding. Here, we investigated this issue by monitoring the effects of RA on phorbol-12-myristate 13-acetate (PMA), tumor necrosis factor (TNF)-α, and interleukin (IL)-1β, and on cecal ligation and puncture (CLP)-mediated EPCR shedding and underlying mechanisms. Data showed that treatment with RA resulted in potent inhibition of PMA, TNF-α, IL-induced EPCR shedding by suppression of TACE expression. In addition, RA reduced PMA-stimulated phosphorylation of p38, extracellular regulated kinases (ERK) 1/2, and c-Jun N-terminal kinase (JNK). These results suggest the potential for use of RA as an anti-sEPCR shedding reagent against PMA, TNF-α, IL-1β and CLP-mediated EPCR shedding.     

New immunomodulatory role of neuropeptide Y (NPY) in Salmo salar leucocytes

Neuropeptide Y (NPY) plays different roles in mammals such as: regulate food intake, memory retention, cardiovascular functions, and anxiety. It has also been shown in the modulation of chemotaxis, T lymphocyte differentiation, and leukocyte migration. In fish, NPY expression and functions have been studied but its immunomodulatory role remains undescribed. This study confirmed the expression and synthesis of NPY in S. salar under inflammation, and validated a commercial antibody for NPY detection in teleost. Additionally, immunomodulatory effects of NPY were assayed in vitro and in vivo. Phagocytosis and superoxide anion production in leukocytes and SHK cells were induced under stimulation with a synthetic peptide. IL-8 mRNA was selectively and strongly induced in the spleen, head kidney, and isolated cells, after in vivo challenge with NPY. All together suggest that NPY is expressed in immune tissues and modulates the immune response in teleost fish.     

血清对U937细胞分化成熟及细胞周期的影响

目的探讨血清对U937细胞分化成熟及细胞周期的影响。方法应用乙酸肉豆蔻佛波醇（PMA）诱导U937细胞分化,血清作为调节因素,通过倒置显微镜观察细胞的形态与贴壁情况并计算细胞贴壁率并依此作为细胞分化成熟的标志,采用流式细胞仪测定细胞周期的变化。结果 FCS＋PMA组细胞贴壁生长;其他3组细胞悬浮生长;细胞周期测定结果显示,与FCS组相比,NOFCS、NOFCS＋PMA和FCS＋PMA组的G1期细胞明显增多,S期细胞明显减少（P〈0.05）。NOFCS＋PMA组经血清恢复后细胞贴壁率明显升高,与FCS＋PMA组相比有显著性差异（P〈0.05）,与NOFCS＋PMA组相比细胞周期无明显差异。NOFCS组经血清恢复后,细胞悬浮生长,细胞周期与NOFCS组相比G1期细胞下降,S期细胞明显增多（P〈0.05）;血清加PMA组在无血清培养与血清培养条件下,细胞都贴壁生长,二者贴壁率没有改变,细胞周期无显著差异。结论血清促进PMA诱导的U937细胞分化成熟并调节细胞周期的变化。     

Critical role of caspases in the regulation of apoptosis and proliferation of mucosal T cells

BACKGROUND & AIMS: Caspases are critical mediators of apoptosis and proliferation of peripheral blood T cells (PBT), but their role in lamina propria T cells (LPT), a cell population highly susceptible to apoptosis, has not been explored. METHODS: RA(+), RO(+) PBT, and LPT were activated with CD3, CD2, and CD28 antibodies, and caspase activity, apoptosis, and proliferation were measured by a fluorometric assay, DNA content, and thymidine incorporation, respectively. Levels of FLIP, an endogenous inhibitor of caspase 8, were measured by immunoblotting. RESULTS: In RA(+) and RO(+) PBT, activation leads to significant increase of caspase activity but not cell death, whereas in LPT a lower elevation of caspase activity was followed by a marked degree of apoptosis. Based on the results of its inhibition, caspase 8 seemed to be essential for LPT apoptosis but, in contrast to RA(+) PBT, had no effect on proliferation. In addition, compatible with their differential susceptibility to apoptosis, levels of FLIP were lower in LPT than PBT. CONCLUSIONS: The high susceptibility of LPT to apoptosis is associated with a distinct regulation of caspase 8 activity, which seems to reflect their mucosal origin rather than simply their memory status. This unique behavior may allow proper control of mucosal T-cell proliferation while still permitting elimination by apoptosis in the face of excessive antigenic pressure.