Suppression of the proliferative response of human lymphocytes to cultured allogeneic HeLa cells by zinc

Zinc added to the culture medium caused a dose-related suppression of the proliferative response of human lymphocytes to cultured allogeneic HeLa cells without any significant decrease in cell viability. In contrast to the response to HeLa cells, this metal ion moderately enhanced T lymphocyte response to mitogens such as phytohemagglutinin (PHA), concanavalin A (ConA) and 12-O-tetradecanoylphorbol-13-acetate (TPA). These findings seem to indicate that zinc may be a crucial factor for the modulation of the T lymphocyte function. It can also be considered that the different effect of zinc on the proliferative responses of lymphocytes to allogeneic HeLa cells and to some soluble mitogens might reflect a difference in mechanisms between the two proliferative responses.     

Effect of mercuric chloride on the proliferative response of human lymphocytes to cultured HeLa cells or a lectin

Proliferative responses of human lymphocytes to cultured allogeneic HeLa cells and to PHA were employed as in vitro cellular immune systems to investigate effects of mercuric chloride on the both proliferative responses. When stimulator HeLa cells were pretreated with mercury, proliferative response of lymphocytes to HeLa cells in the mixed cell culture was suppressed dose-dependently. The response of lymphocytes treated with mercury to HeLa cells was suppressed markedly, even at 15-min exposure to 1 X 10(-5) M HgCl2. The response of lymphocytes to PHA as well as that to HeLa cells was suppressed by mercury treatment, even at 15-min exposure. A possible mechanism for the suppressive effect of mercury on the mixed cell reaction was discussed; mercury modification of molecules at the cell surface of the stimulator cells or responder cells and effects of mercury on macrophages.     

nmhaFGF对人乳腺癌细胞增殖的影响及相关机制

目的比较nmhaFGF和haFGF对恶性肿瘤细胞的促增殖作用及其机制，探讨nmhaFGF临床应用的安全性。方法以haFGF和nmhaFGF分别处理人乳腺癌细胞(MCF-7)，用MTT法检测其细胞增殖活性；用流式细胞技术分析细胞周期；用蛋白免疫印迹法半定量检测MAPK通路中的信号蛋白Grb2和ERK1/2在MCF-7中的表达。结果nmhaFGF对MCF-7细胞的促增殖作用明显低于haFGF；haFGF组G₁/G₀和G₂/M期细胞比例均低于nmhaFGF组和对照组，S期细胞比例显著高于nmhaFGF组和对照组；nmhaFGF组的Grb2和ERK1/2信号蛋白表达水平均低于haFGF组，亦接近对照组。结论nmhaFGF的促增殖活性显著下降，其机制是通过下调MAPK信号通路中的Grb2和ERK1/2信号分子的表达来实现的。     

Effects of hexachlorocyclohexane isomers on the mitogenic response of bovine lymphocytes.

The α-, β-, γ- and δ-isomers of hexachlorocyclohexane (HCH) were evaluated as modifiers of the mitogenic response in cultured bovine lymphocytes. None of the four isomers were mitogenic alone; however, the concurrent administration of αHCH and phytohemagglutinin-P (PHA) stimulated DNA synthesis in lymphocyte cultures 2.2-fold over that obtained with PHA alone. βHCH was inactive in the test system whereas both γ- and δHCH severely inhibited the PHA response. Treatment of lymphocytes with the microsomal enzyme inhibitor SKF-525A blocked the co-mitogenic activity of αHCH without affecting the basal PHA response. The role of hexachlorocyclohexane-sensitive metabolic systems in the regulation of mitogenesis in lymphocytes is discussed.     

The effects of nitrogen mustards on the proliferative and Ig synthetic response of human peripheral blood lymphocytes

Maximal inhibition of pokeweed mitogen-stimulated Ig production and [3H]thymidine incorporation was shown to occur when unfractionated human peripheral blood mononuclear cells were cultured with concentrations of the nitrogen mustards melphalan, mechlorethamine or chlorambucil in the 20-100-microM range, whereas concentrations of microsome-activated cyclophosphamide (A-Cy) in the 2-mM range were required for equivalent inhibition. Around 400 microM A-Cy, IgM secretion was not inhibited, but secretion of IgA and IgG was. The [3H]thymidine incorporation of enriched populations of both large and small B and T cells all showed about 20-50-fold greater sensitivity to melphalan than to A-Cy, despite a difference of only 6-fold in alkylating activity between these drugs. Large (250 micron 3) B and T cells were only marginally more sensitive to melphalan and A-Cy than small (210 micron 3) T and B cells. Kinetic studies showed that IgG and IgA secreted by day 7 could be maximally inhibited by melphalan added as late as day 3, and IgM synthesis as late as day 2. In contrast, inhibition of Ig production by A-Cy steadily declined after the first day, especially IgM, which was no longer inhibitable by A-Cy on day 3. Inhibition of cumulative Ig production did not occur when A-Cy or melphalan was added on day 5 or later. Cell recombination experiments performed with drug pulsed and untreated monocytes plus B cells and irradiated T cells showed that inhibition of [3H]thymidine or Ig production was most striking when monocytes + B cells (rather than T cells) were exposed to melphalan in the first 16 h. When A-Cy was used in the first 16 h, inhibition of Ig production was partial and inconsistent, and inhibition of monocytes + B cell or T cell [3H]thymidine incorporation was not evident. We conclude that the nitrogen mustards melphalan and A-Cy can inhibit pokeweed mitogen-stimulated DNA synthesis by human T or B cells and Ig production in vitro, but that their mechanisms of action differ.     

D-氨基葡萄糖盐酸盐诱导淋巴细胞增殖及其机制

目的研究D-氨基葡萄糖盐酸盐(GAH)对小鼠淋巴细胞增殖及其作用机制。方法利用荧光染料CFSE为细胞标记,研究GAH对小鼠淋巴细胞增殖的影响。激光共聚焦显微镜、流式细胞仪分别检测GAH对细胞内Ca2+浓度、钙调蛋白(CaM)表达的影响。结果GAH可使淋巴细胞增殖。加入GAH 2,4,6 h后,细胞内Ca2+浓度与对照组相比显著升高。GAH作用72 h后,细胞内CaM阳性表达细胞的百分率与对照组相比显著增加,由(61.80±0.97)%增至(79.21±0.95)%,说明GAH能够诱导淋巴细胞内CaM表达增加。结论GAH能够提高淋巴细胞内Ca2+浓度,促进CaM表达,触发Ca2+信号通路,活化淋巴细胞增殖。     

Nicotine suppresses the proliferative response of peripheral blood lymphocytes in rats

Nicotine, the psychoactive ingredient of cigarette smoke, alters lymphocyte function in vitro. However, unlike tobacco smoke, the immunologic effects of nicotine in vivo have not been determined. In the present study a single SC administration of 0.33, 0.66, or 1.32 mg/kg (free base) of nicotine bitartrate to male rats produced a dose-dependent decrease in the in vitro proliferative response of blood lymphocytes to the T-cell mitogen Con A when sampled 1 hr after nicotine administration. These results strongly suggest that acute nicotine exposure can induce immune perturbation in vivo. Nicotine also increased plasma corticosterone (CORT) and there was a substantial negative correlation (r = ?.52) between CORT levels and the extent of proliferation (DPM) for the optimal Con A dose. The correlation between nicotine's immunologic and CORT effects is discussed within the context of several other potential mediators of nicotine's effects. © 1992 Wiley-Liss, Inc.     

海兰地嗪对血小板聚集的影响及机理探讨

海兰地嗪(Her)体外对胶原,ADP,A23187和AA诱导的大鼠血小板聚集有明显抑制作用,其IC_(50)分别为14.5,41.6,44.1和48.3μg/ml。Her对AA诱导的大鼠血小板MDA生成不能抑制,但能升高兔血小板cAMP水平和抑制凝血酶诱导的人血小板胞浆内游离钙离子浓度升高。Her的抗血小板聚集作用机理可能与升高血小板内cAMP水平和抑制细胞内游离钙离子浓度升高有关。     

beta-Adrenergic responsiveness of human peripheral lymphocytes after mitogenic transformation with phytohemagglutinin

In vitro transformation of human peripheral blood lymphocytes with the mitogen phytohemagglutinin did not alter the total number of beta-adrenergic binding sites for (+/-)-125iodocyanopindolol on the surface of intact cells, whereas binding to membrane fragments of transformed cells appeared to be diminished. In isolated membranes, there was also a marked decrease in basal, fluoride- and hormone-stimulated adenylate cyclase activity after phytohemagglutinin treatment. In whole cells, however, a lowering effect of phytohemagglutinin on levels of cyclic adenosine 3',5'-monophosphate was not apparent. The discrepancy between data on intact and broken cells indicates that the transformed cells do not acquire additional beta-adrenergic receptors or catalytic adenylate cyclase as their cell surface expands due to blastogenesis. It is therefore concluded that mitogenic transformation of human peripheral lymphocytes does not cause specific changes in the beta-adrenergic/adenylate cyclase system.     

Lymphocyte proliferation in glutathione-depleted lymphocytes: direct relationship between glutathione availability and the proliferative response

Lymphocyte proliferation in response to mitogenic lectins is directly dependent upon glutathione (GSH) availability. Thus, proliferation can be enhanced by providing lymphocytes with excess glutathione, and strongly inhibited by limiting the quantity of intracellular GSH available during the mitogenic stimulation. Exogenous GSH, cysteine and 2-mercaptoethanol (2-ME) can all significantly enhance lymphocyte proliferation and augment intracellular GSH levels. Lymphocytes depleted of GSH by buthionine sulfoximine (BSO) fail to undergo a full blast transformation response to mitogenic lectins. In lymphocytes stimulated with mitogen in the presence of BSO, the time profile of intracellular GSH levels shows a rapid decline over the first 24-48 h and a subsequent gradual decline to levels less than 0.5 nmol/10(7) lymphocytes by 72-96 h. Exogenous GSH partially sustains intracellular GSH levels and completely restores lymphocyte proliferation even in the presence of 2000 microM BSO. Other thiols, such as cysteine and 2-ME, do not significantly alter the time profile of intracellular GSH in mitogen-stimulated lymphocytes in the presence of 2000 microM BSO, and their capacity to enhance proliferation is greatly diminished albeit not completely abolished under these conditions. Ongoing GSH synthesis is clearly essential to maintain a normal proliferative response. If intracellular GSH levels are depleted initially and lymphocytes are then stimulated with mitogen in the presence of BSO, there is a diminished capacity of cysteine and 2-ME to restore proliferation relative to exogenous GSH. There is also a diminished capacity of exogenous GSH to restore proliferation with higher concentrations of BSO. This suggests that the restoration of lymphocyte proliferation by exogenous GSH is more closely linked to effects on intracellular rather than extracellular GSH. These studies confirm the importance of intracellular GSH in lymphocyte proliferation. The essential role for intracellular GSH can be demonstrated even in the presence of other exogenous thiols, such as cysteine and 2-ME. The enhancement of lymphocyte proliferation by exogenous cysteine appears to be directly linked to effects on intracellular GSH, whereas the enhancement by 2-ME is probably more complex but clearly linked to effects on intracellular GSH.     

黄芩苷对肺腺癌细胞多药耐药性的影响及机制

目的探讨黄芩苷对人肺腺癌细胞株A549多药耐药性(MDR)的影响及作用机制。方法体外培养人肺腺癌细胞株A549后给予0、0.5、1、2、4、8mg/L黄芩苷对细胞进行处理,MTT法检测不同浓度黄芩苷对A549细胞生长的影响情况;逆转录-聚合酶链反应法(RT-PCR)检测各组细胞多药耐药基因1(MDR-1)、多药耐药相关蛋白-1(MRP1)、谷胱苷肽转移酶-π(GST-π)、拓扑异构酶(TOPO)ⅡαmRNA的表达情况。结果与对照组相比,黄芩苷组细胞生长明显受到抑制(P<0.05或<0.01);黄芩苷处理后肿瘤细胞MDR-1、MRP1、GST-π、TOPOⅡαmRNA表达水平降低,与对照组比较差异均有统计学意义(P<0.01)。结论 baicalin可以调节多种MDR基因的表达,具有明显的逆转肺腺癌细胞MDR的作用。     

Effect of combined treatment with paroxetine and transcranial magnetic stimulation (TMS) on the mitogen-induced proliferative response of rat lymphocytes

Depression is associated with abnormal functions of the immune system. In this study, we investigated how two modem antidepressant therapies, chronic treatment with transcranial magnetic stimulation (TMS) and administration of an antidepressant belonging to selective serotonin reuptake inhibitors (SSRI), paroxetine, affect the proliferative response of thymocytes and splenocytes stimulated in vitro with various mitogens. Paroxetine (10 mg/kg) and TMS (B = 1.2 T, f = 30 Hz, t = 330 s) were applied once daily for 12 consecutive days, while, if given jointly paroxetine was injected 30 min before TMS. The mitogens used were: concanavalin A (Con A), pokeweed mitogen (PWM) or lipopolysaccharide (LPS). While either treatment applied alone had no effect on proliferative response, the joint application of paroxetine and TMS significantly depressed it. The literature data suggest that pulsed magnetic field may directly inhibit mitogen-activated lymphocyte proliferation, which is also inhibited by the presence of high level of serotonin. The present results suggest that both effects are additive, and because of that application of both treatments, whose effects alone are insufficient to prompt the reaction, possibly because adaptive changes during chronic treatment, results in a significant inhibition of lymphocyte proliferation.     

复方隔山消颗粒对胃肠运动的影响

目的:探讨复方隔山消颗粒对胃肠运动的影响及其机制。方法:用硫酸阿托品抑制小鼠小肠推进运动,观察复方隔山消颗粒对小肠推进运动的影响;以夹尾刺激法制造大鼠功能性消化不良模型,观察复方隔山消颗粒对模型大鼠胃黏膜一氧化氮(NO)含量和血中胃肠激素水平的影响。结果:复方隔山消颗粒能明显提高小肠运动受抑小鼠的小肠推进功能,显著降低功能性消化不良大鼠胃黏膜NO含量,明显升高其血清胃泌素(GAS)和血浆胃动素(MTL)含量。结论:复方隔山消颗粒能促进胃肠运动,其机制可能与其降低胃黏膜NO含量,提高血清GAS和血浆MTL水平有关。     

Anti-hyperlipidemic effect of iodine eggs: studies on the mechanism of its action

The anti-hyperlipidemic effect of the iodine egg was found to be in the neutral lipid (NL) fraction in its yolk. For the purpose of clarifying the hypolipidemic effect of the iodine-containing NL fraction, the effect of clofibrate (CPIB) was investigated. CPIB was found to lower TC, atherogenic index [(TC-HDL cholesterol)/HDL cholesterol], TG and FFA, but not FC; while NL lowered TC, FC and the atherogenic index, but not TG and FFA. Cholesterol metabolites, probably metabolized in the liver, were examined. Hepatic cholesterol level was increased by NL and CPIB. The ratio of fecal bile acid of the excretion type, lithocholic acid (LCA) to deoxycholic acid (DCA), increased when NL and CPIB were administered, but the hepatic HMG-CoA reductase activity, responsible for the endogenous cholesterol synthesis, was not altered. Thus, the anti-hyperlipidemic mechanism of NL may be the mobilization of peripheral cholesterol to the liver, probably for the disposal by excretion as bile acids.     

The effects of flurbiprofen and indomethacin on the mitogenic response of human peripheral mononuclear cells

The effects of flurbiprofen (FBP) and indomethacin (INDO) on the incorporation of [³H]thymidine into human peripheral mononuclear cells after stimulation with phytohaemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) were investigated. FBP and INDO enhanced [³H]thymidine incorporation only at suboptimal concentrations of PHA and Con A but the concentration of PWM was less critical.Enhancement depended upon the presence of mononuclear cells which could be removed by adherence to plastic: these may be tentatively identified as monocytes (macrophages). INDO enhanced [³H]thymidine uptake to a greater degree than FBP and its effect was decreased to a greater extent by removal of monocytes.The enhancing effects of INDO and FBP are completely reversible by thorough washing of cells which had been exposed to the drugs and could be regained by direct addition of drugs to previously washed cells. Concurrent addition of both drugs to cell cultures showed neither antagonism nor synergy with respect to the effect of one drug alone. PGE₂ inhibited [³H]thymidine incorporation. Like that of FBP and INDO, this action was dependent on mitogenic dose and apparent at suboptimal doses only. A low concentration of exogenous PGE₂ (2 ng/ml) was sufficient to prevent the enhancing effect of both FBP and INDO.     

Differential effects of arsenic on intracellular free calcium levels and the proliferative response of murine mitogen-stimulated lymphocytes

This study examined the effects of sodium arsenite treatment on free [Ca(2+)]i and cell death in mitogen-activated murine lymphocytes. The main findings of this study were that simultaneous sodium arsenite treatment inhibited PHA- but not Con A-induced T cell proliferation, induced a higher increase in free [Ca(2+)]i and an early increase in the proportion of dead cells in PHA than in Con A activated cells. Sodium arsenite pre-treatment reduced both PHA- and Con A-induced T-cell proliferation. Phorbol myristate ester (PMA) did not prevent the inhibitory effects of both sodium arsenite treatments, suggesting that sodium arsenite did not significantly decreased PKC activation or that its effects occurred on events parallel to PKC activation. Both PHA and Con A increased free [Ca(2+)]i after stimulation, yet the effect was more pronounced in mitogen-activated cells simultaneously treated with sodium arsenite and particularly in those activated with PHA. The increase in free [Ca(2+)]i was in agreement with the early cell death induced by sodium arsenite in PHA-activated cells, a finding consistent with the inhibitory effects on PHA-induced proliferation. Sodium arsenite-induced cell death occurred faster in PHA-activated cells. Further studies are needed to ascertain the relationships between the effects of sodium arsenite on free [Ca(2+)]i levels and the type of cell death induced by sodium arsenite and their relevance for the proliferative response of T cells.     

The effect of desferrioxamine on the proliferative response of rat lymphocytes stimulated with various mitogens in vitro

This paper reports experiments designed to evaluate the effect of desferrioxamine on lymphocytes obtained from the spleen of Sprague-Dawley rats. The results showed that desferrioxamine inhibits the proliferative response of lymphocytes stimulated by concanavalin A or pokeweed mitogen, the effect being proportional to the dose used, and being maximal at the end of the culture period. To exert its effect, desferrioxamine has to be present from the initiation of the cultures--its addition 24 h later markedly reduced its inhibitory effect. Studies of cell viability indicated that the inhibition was not due to toxicity. Lymphocytes obtained from young animals (4 to 12-week-old) were more sensitive to desferrioxamine than older animals (13 to 18-week-old). Saturation of desferrioxamine with iron abolished its effect, suggesting a direct relationship between chelating properties and inhibition, and reinforcing the hypothesis that iron plays an important role in the process of cell division.