Modulation of Structural and Functional Properties of Human Lymphocytes by Reactive Oxygen Species

Bulletin of Experimental Biology and Medicine - The effects of ROS on functional properties (cytotoxic activity, antibody-producing activity, TNFα synthesis, and free cytosol calcium level),...     

MK-801对新生鼠脑外伤性神经变性的超微结构的影响

目的:研究非竞争性N-甲基-D-天门冬氨酸受体拮抗剂MK-801对新生鼠创伤性颅脑损伤(TBI)后同侧顶叶皮质和海马神经元超微结构的影响.方法:新生7 d SD大鼠,被随机分成正常对照组和实验组(实验组给予MK-801 1 mg/kg,并且细分为创伤前30 min给药、创伤即刻给药和创伤后30 min给药3个亚组).造模24 h取材,透射电镜下观察神经细胞超微结构的变化.结果:创伤后30 min给药的神经细胞出现胞质和核染色质的浓缩深染,胞质内充满大小不等的空泡;创伤即刻组的神经细胞胞质内线粒体有肿胀,但胞核的变化不明显.结论:适时和适量运用MK-180能延迟神经细胞核染色质和粒线体的变性损伤,使之停留在损伤早期,为临床联合其他药物治疗赢得时间.     

Expression of adhesion molecules on cord-blood-derived, cultured human mast cells and effect of dexamethasone on intercellular adhesion molecule-1 expression on the mast cells treated by phorbol myristate acetate

BACKGROUND: Increase in mast-cell number at sites of allergic inflammation has been observed, and glucocorticoids applied to the sites have been shown to result in a significant reduction in mast cells. However, the expression of adhesion molecules on cultured human mast cells and their regulation by glucocorticoids is poorly understood. METHODS: Cultured human mast cells were raised from human umbilical cord-blood cells, and the expression of adhesion molecules on the mast cells was analyzed by flow cytometry. The cells were also incubated with 10 ng/ml phorbol myristate acetate (PMA) for the indicated time, and the effect of dexamethasone on adhesion molecule expression on PMA-treated, cultured human mast cells was examined. RESULTS: Cord-blood-derived, cultured human mast cells constitutively expressed intercellular adhesion molecule-1 (ICAM-1), very late antigen-4 (VLA-4), and macrophage-1 antigen (Mac-1). Weak expression of lymphocyte function-associated antigen-1 (LFA-1) was observed on the cells, whereas they failed to express vascular cell adhesion molecule-1 (VCAM-1). Kinetic studies showed that after a transient downregulation reaching a minimum at 8 h, the expression of ICAM-1 was markedly upregulated on PMA-treated mast cells after a 24-h incubation. In contrast, the expression of VLA-4 and Mac-1 was decreased after the incubation with PMA for 24 h. The PMA-induced upregulation of ICAM-1 was inhibited by dexamethasone in a concentration-dependent manner. CONCLUSION: Our results indicate that cord-blood-derived, cultured human mast cells constitutively express integrins and ICAM-1, but not VCAM-1, and demonstrate for the first time that dexamethasone inhibits the upregulation of ICAM-1 on PMA-treated, cultured human mast cells.     

Chemoattractant- and Mitogen-Induced Generation of Reactive Oxygen Species in Human Lymphocytes: The Role of Calcium

This study examined the role of calcium in the generation of reactive oxygen species (ROS) in human lymphocytes activated by the chemoattractant formyl-Met-Leu-Phe (fMLP) and the T-cell mitogen phytohaemagglutinin (PHA). The concentrations of cytosolic calcium ([Ca2+]i) and ROS were monitored simultaneously with a fluorescence spectrophotometer after the cells had been incubated in fura-2 (calcium-sensitive dye) and 2',7'-dichlorofluorescein diacetate (DCF-DA, ROS-sensitive dye). The lymphocytes were stimulated with fMLP (200 nmol l-1) or PHA (10 micromol l-1) in the absence and presence of extracellular calcium. A dose-response test was also conducted for extracellular calcium. fMLP and PHA significantly increased both [Ca2+]i (P < 0.001) and ROS concentrations (P < 0. 001) above the control levels in the presence of extracellular calcium. However, such increases were abolished in the absence of extracellular calcium, suggesting total dependence of the responses to both fMLP and PHA on transplasma-membrane calcium influx. There were also graded increases in ROS with increasing concentrations of extracellular calcium. The results show that transplasma-membrane calcium influx is essential for fMLP- and PHA-induced generation of reactive oxygen species in human lymphocytes.     

Role of NMDA receptors in the increase of glucose metabolism in the rat brain induced by fluorocitrate

The effect of inhibition of glial metabolism by infusion of fluorocitrate (FC, 1 nmol/μl, 2 μl) into the right striatum of the rat brain on the glucose metabolism was studied. Significant increases in [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) uptake (45 min) in the right cerebral cortex and striatum were observed 4 h after the infusion of FC, both as determined by the tissue dissection method and autoradiography. No significant increase in the initial uptake of [¹⁸F]FDG (1 min) was seen in the striatum. Pretreatment with dizocilpine (MK-801), an N-methyl-d-aspartate (NMDA) receptor antagonist, reduced [¹⁸F]FDG uptake in not only FC infused hemisphere but also in the contralateral hemisphere (saline-infused side). The radioactivity concentrations in plasma at 1, 5 and 45 min after the [¹⁸F]FDG injection were not altered by MK-801. This effect of MK-801 on glucose metabolism observed in the rat brain infused with FC was different from previous reports which indicated an increase in glucose metabolism in some areas of normal rat brain. In addition, the enhancement of glucose metabolism in the striatum induced by FC was almost completely abolished by pretreatment with MK-801. In the cerebral cortex, the relative ratio of radioactivity concentration in the right hemisphere to that in the left hemisphere still remained 1.37 (tissue dissection method) or 1.55 (autoradiography), which indicated that MK-801 partially blocked the effect of FC of enhancing glucose metabolism in this region. These results indicate an important role of NMDA-mediated signal transmission on the increase of glucose utilization induced by inhibition of glial metabolism.     

心脉灵注射液对培养神经细胞谷氨酸损伤的影响

目的:观察心脉灵注射液和MK-801对谷氨酸所致的培养神经细胞损伤的作用。方法:制备培养神经细胞谷氨酸损伤模型,测定上清液中一氧化氮和丙二醛的含量,同时相差显微镜下观察活细胞的形态改变。结果:MK-801和心脉灵液可使谷氨酸致神经细胞形态损伤得到减轻,并可使培养上清液中增高的一氧化氮和丙二醛含量显著低于谷氨酸组。结论:心脉灵液在细胞水平上具有神经元保护作用.     

Effect of phorbol myristate acetate on T cell colony formation, interleukin-2 (IL-2) receptor expression and IL-2 production by cells from patients at all stages of HIV infection.

We and others have shown that several T cell responses induced by the mitogen phytohaemagglutinin (PHA), including T cell colony formation, IL-2 receptor (IL-2R) expression, and IL-2 production are impaired in patients with AIDS and lymphadenopathy syndrome (LAS). We investigated whether phorbol myristate acetate (PMA) could act in synergy with PHA (as it does in healthy subjects) to enhance in vitro T cell responses of patients at all stages of infection by HIV. In AIDS patients with opportunistic infections (AIDS/OI), PHA + IL-2 + PMA led to a total disappearance of T cell colonies in 10/11 patients, among whom six already displayed very low numbers of colonies induced by PHA + IL-2 (less than 50 colonies/5 x 10(4) cells). In contrast, T cell colony formation induced by PHA + IL-2 + PMA was maintained or increased, compared with that induced by PHA + IL-2, in five out of six AIDS patients with Kaposi's sarcoma (AIDS/KS), 10/14 LAS and six out of seven HIV-seropositive asymptomatic (HIV+/AS) homosexuals. In these three groups of patients, a low percentage of colony cells induced by PHA + IL-2 + PMA expressed CD3 and CD4 molecules, but 50-89% of cells were IL-2R (Tac) positive, as in healthy controls. Studies on T cell activation and IL-2 production were performed on a selected group of 12 HIV-infected patients for whom sufficient numbers of lymphocytes could be obtained. PMA induced CD4 down-modulation in controls and in HIV-infected patients. However, CD3 down-modulation and induction of the Tac chain of IL-2R by PMA were significantly impaired in patients, compared with controls, and these two parameters were correlated. Although PHA alone induced virtually normal levels of Tac antigen on patients' cells, Tac induction by PHA + PMA was significantly decreased in patients versus controls. Cells from five out of 10 patients tested failed to produce detectable amounts of IL-2 after PHA stimulation, whereas IL-2 production increased significantly in all patients tested (n = 9) after PHA + PMA, with a level of IL-2 activity significantly higher than in controls. No correlation was found in this group of patients between the effects of PMA + PHA on T cell colony formation, Tac expression, or IL-2 production, as compared with PHA alone. Taken together, our results indicate that in vitro T cell functional studies with PMA may be useful to evaluate better the defects of T cell activation in HIV-infected patients.     

免疫电镜观察培养脊髓神经元中微管相关蛋白-5的表达

目的　研究微管相关蛋白 5在培养脊髓神经元的表达变化。方法　使用ACLAR膜培养脊髓神经元 ,分为四组 ,即正常脊髓神经元组 ,加诺考达唑 (nocodazole)组 ,加乙酸佛波醇 (PMA)组 ,空白对照组。免疫电镜观察四组微管相关蛋白 5的分布。结果　正常脊髓神经元微管相关蛋白 5阳性颗粒在胞浆及突起中均匀分布 ,nocodazole引起微管相关蛋白 5阳性颗粒排列紊乱 ,PMA则使微管相关蛋白 5阳性颗粒在胞浆及突起中密集存在。结论　微管相关蛋白 5在脊髓神经元的胞浆及突起中均有表达 ,并受nocodazole及PMA的调节     

活性氧簇介导的氧化应激及细胞焦亡在大鼠脑缺血再灌注损伤中的作用

目的 研究活性氧簇 (ROS) 介导的氧化应激及细胞焦亡在大鼠脑缺血再灌注 ( I/ R) 损伤中的 作用。 方法 成年雄性 SD 大鼠分为假手术 ( Sham) 组、 I/ R 组、 ROS 清除剂 N 乙酰半胱氨酸-低剂量 (NAC-L) 组、 NAC 中等剂量 (NAC-M) 组、 NAC 高剂量 (NAC-H) 组, 建立脑 I/ R 损伤模型并给予 50、 100、 200 mg / kg NAC 腹腔注射干预。 再灌注后 24 h, 评价神经功能, 检测脑梗死面积百分比、 ROS、 丙二 醛 (MDA)、 4-羟基壬烯醛 (4-HNE)、 总抗氧化力 (T-AOC)、 裂解型 caspase-1 (Cleaved caspase-1)、 gasdermin D 的 N 端片段 (GSDMD-N)。 结果 I/ R 组脑梗死面积百分比、 ROS、 MDA、 4-HNE 含量、 Cleaved caspase-1、 GSDMD-N 表达水平均明显增加, T-AOC 含量明显降低 ( P < 0. 05 ); NAC-L 组、 NAC-M 组、 NAC-H 组脑梗死面积百分比、 ROS、 MDA、 4-HNE 含量、 Cleaved caspase-1、 GSDMD-N 表达水平均明显降 低, T-AOC 含量明显增加 (P< 0. 05) 且 NAC 剂量越高, 上述变化越显著。 结论 ROS 介导的氧化应激及 细胞焦亡参与大鼠脑 I/ R 损伤。     

Regulation of Reactive Oxygen Species Production by Peripheral Blood Neutrophils from Women with Postpartum Endometritis

Production of reactive oxygen species in unfractionated peripheral blood increased in parturient women without postpartum infectious complications and patients with postpartum endometritis. The control group included nonpregnant women with normal reproductive function. Intergroup differences were revealed in the degree of respiratory burst activation with opsonized zymosan and response of isolated granulocytes to chemotactic peptide N-formyl-Met-Leu-Phen (1 μM). Production of reactive oxygen species tended to normal after therapy. We studied the effects of a specific mitogen-activated protein kinase p38MAPK inhibitor and inhibitors of tyrosine protein phosphatases and phosphatidylinositol-3-kinase. The role of p38MAPK in reactive oxygen species generation by cells changes significantly in parturient women. __________ Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 140, No. 8, pp. 173–176, August, 2005     

NMDA receptors are involved in Ginkgo extract-induced facilitation on memory retention of passive avoidance learning in rats

Herbal therapies are commonly used to enhance memory and learning. Ginkgo biloba has shown to be one of the most popular herbs that is used to treat amnesia and retard age related memory deficits. Although, there have been several reports on the memory enhancing effects of Ginkgo, involvement of glutamatergic system that plays pivotal role in learning and memory has not been precisely assessed so far. The current study intended to investigate the effect of Ginkgo intake on amnesia while NMDA (N-methyl D-aspartic acid) receptors blocked by the administration of MK-801. The study used passive avoidance (PA) task to investigate the effect of chronic administration of Ginkgo extract (40 and 90 mg/kg; oral) on the memory span in male Wistar rats, suffering from MK-801-induced forgetfulness (0.06 and 0.1 mg/kg; i.p.). The results indicate that Ginkgo was able to remove MK-801-induced forgetfulness, indicating that Ginkgo can affect memory retention but not effect on passive avoidance acquisition, using pathways other than glutamatergic system as well. The results might indicate that Ginkgo extract can be effective in removing forgetfulness caused by inhibiting NMDA receptors from performing their activities.     

C5a-induced chemiluminescence of human granulocytes and its amplification by a serum factor

Purified human C5a elicits a fast chemiluminescence (CL) response from isolated human granulocytes in the presence of Lucigenin (bis-N-methylacridinium nitrate). The reaction is inhibitable to more than 90% by superoxide dismutase (SOD) - final concentration 200 micrograms/ml -, to about 60% by catalase - final concentration 10 mg/ml - and to 30% by the hydroxyl radical scavenger D-mannit - final concentration 100 mM. Therefore O2- seems to be the oxygen radical responsible for most of the CL, while OH and H2O2 are also involved. Addition of normal pool serum to the cells for 1-2 min before stimulation with C5a strongly enhances the effect in a dose and time-dependent manner. Therefore the existence of a "helper activity" in serum amplifying the C5a-induced CL of granulocytes is postulated. This "helper activity" is, however, no specific for C5a, since CL responses elicited with the chemotactic peptide f-met-phe or by phorbol-myristate-acetate (PMA) are also enhanced by preincubation with serum. In contrast, ConA-induced CL is not enhanced but decreased. Therefore, though not unique to C5a-induced CL, the "helper activity" seems not to represent a general "adjuvans" effect of serum on the granulocytes, but to be restricted to certain stimuli.     

MK-801对新生大鼠脑外伤后神经元凋亡的影响

目的：探讨N-甲基-D-天冬氨酸(NMDA)受体拮抗剂MK-801对新生大鼠创伤性脑外伤(traumatic brain injury,TBI)后神经元凋亡的影响。方法：建立新生7 d大鼠顶叶皮质挫伤模型,在TBI前30 min、TBI后即刻、TBI后30 min分别给予腹腔注射MK-8011 mg/kg,在TBI后24 h取脑,连续切片,行H-E染色和Caspase-3免疫组化染色,检测脑神经元细胞的损伤和凋亡。结果：MK-801三组不同时间用药组与TBI组相比,在创伤同侧的扣带皮质、顶叶皮质和丘脑神经元凋亡细胞数减少,有显著性差异。其中TBI后即刻用MK-801治疗效果最好。结论：MK-80l能明显减少TBI后神经元的凋亡。     

Method for In Situ Evaluation of Superoxide Production by Pulmonary Macrophages in the Rat

In order to investigate superoxide production by pulmonary macrophages in the rat, a route was created by ligating both the inferior and superior venae cavae and resecting the aorta after cannulation through the inferior vena cava into the right atrium of the heart. Lung perfusion was performed via this route with nitro blue tetrazolium. Although there was no formazan deposition throughout the lung, it became detectable in both alveolar and interstitial macrophages when phorbol myristate acetate was added to the perfusate. This deposition was markedly enhanced by previous injection of Corynebacterium parvum. The deposition disappeared after further addition of Cu(Lys)₂, a scavenger of superoxide anions. This procedure may be useful for estimating in situ the ability of pulmonary macrophages to produce superoxide in the rat.     

MK-801诱发精神分裂症对大鼠探索能力、疼痛反应及海马神经细胞增殖的影响

目的:观察大鼠精神分裂症后探索能力、痛觉及海马齿状回颗粒细胞层神经细胞增殖的改变。方法:MK-801腹腔注射制备精神分裂症动物模型,分别监测给药后第1、5、10、14 d大鼠的探洞次数和甩尾时间。Brdu标记后取材,应用免疫荧光染色和激光共聚焦显微技术观察海马齿状回神经细胞的增殖情况。结果:①洞板试验:实验组大鼠的探洞次数较对照组显著下降(P<0.01),且随着MK-801给药时间的增加而减少(P<0.01);②甩尾试验:实验组大鼠对疼痛刺激的反应时间较对照组缩短(P<0.01),且随着MK-801给药时间的延长痛觉敏感度不断增加(P<0.01);③神经细胞的增殖:停药后第1 d,实验组海马齿状回颗粒层神经细胞增殖数较对照组减少(P<0.05),第16 d两组间无显著差异(P>0.05)。结纶:MK-801诱发精神分裂症后可致大鼠的探索能力减退、痛觉敏感,同时可降低海马齿状回颗粒细胞层神经细胞的增殖。     

Modifying Effect of Autotransfusion of Mesenchymal Stromal Cells on the Production of Reactive Oxygen Species and Cytokines by Mononuclear Cells in Patients with Chronic Heart Failure

Bulletin of Experimental Biology and Medicine - We studied in vivo modifying effect of autotransfusion of human bone marrow mesenchymal stromal cells on ROS generation and production of cytokines...     

Production and Secretion of Immunoglobulins by in Vitro-Activated Human B Lymphocytes

Activation induced by pokeweed mitogen in cultures of mononuclear cells from human blood was followed sequentially by simultaneous quantitation of live cells, thymidine incorporation, cells displaying cytoplasmic IgM, IgG, IgA or IgD, cells secreting IgM, IgG or IgA and cumulated IgM secretion. Maximal cellular activity was found after 7 days of culture, with means of 16000 IgM-, 20700 IgG- and 9900 IgA-secreting cells per 10⁶ originally cultured cells. The cumulated IgM secretion after 21 days of culture averaged 10400 ng per 10⁶ originally cultured cells. A close correlation was found between the number of IgM-secreting cells and the cumulated IgM secretion.