JAK-STAT通路调制NF-kB介导H2O2预处理的细胞保护作用

目的:探讨核因子-kB(nuclear factor-kB,NF-kB)在H2O3预处理诱导的适应性细胞保护作用中的作用及JAK-STAT通路对NF-kB的调制.方法:在PC12细胞建立H2O2预处理对抗氧化应激(300 μmol/LH2O2)损伤细胞的实验模型.应用碘化丙啶(PI)染色流式细胞术检测细胞凋亡率,免疫印迹法(Western blotting)测定NF-kB和STAT3的表达水平.结果:用100 μmol/L H2O2预处理PC12细胞90 min可显著地抑制300 μmol/LH2O2作用12 h引起的细胞凋亡,并明显地上调NF-kB和STAT3的表达,NF-kB抑制剂MG-132(10 μmol/L)和JAK2抑制剂AG-490(10 μmol/L)均可抑制H2O2预处理引起的适应性细胞保护作用及上调NF-kB表达的作用.结论:JAK-STAT通路调节NF-kB介导的H2O2预处理的细胞保护作用.     

JAK—STAT通路调制NF-κB介导H2O2预处理的细胞保护作用

目的：探讨核因子-κB（nuclearfactor-κB，NF-κB）在H2O2预处理诱导的适应性细胞保护作用中的作用及JAK—STAT通路对NF-κB的调制。方法：在PC12细胞建立H2O2预处理对抗氧化应激（300μmol／LH2O2）损伤细胞的实验模型。应用碘化丙啶（PI）染色流式细胞术检测细胞凋亡率，免疫印迹法（Westem blotting）测定NF-κB和STAT3的表达水平。结果：用1000μmol／L H2O2预处理PC12细胞90min可显著地抑制300panol／L H2O2作用12h引起的细胞凋亡，并明显地上调NF-κB和STAT3的表达，NF-κB抑制剂MG-132（100μmol／L）和JAK2抑制剂AG-490（10izmol／L）均可抑制H2O2预处理引起的适应性细胞保护作用及上调NF-κB表达的作用。结论：JAK-STAT通路调节NF-κB介导的H2O2预处理的细胞保护作用。     

PI3K/AKT通路介导H_2O_2预处理减轻PC12细胞氧化损伤

目的探讨PI3K/AKT信号通路是否参与H2O2预处理诱导的适应性细胞保护作用。方法体外培养PC12细胞,建立H2O2预处理对抗高浓度H2O2诱导细胞损伤的实验模型。应用甲氮甲唑蓝(MTT)法测定细胞的存活率,比色法测定乳酸脱氢酶(LDH)的活性,碘化丙啶(PI)染色流式细胞术检测细胞凋亡率,免疫印迹法(Westernblot)测定AKT的表达。结果 100μmol H2O2预处理PC12细胞90 min可显著地抑制300μmol H2O2引起的损伤,使细胞存活率从50.2%±4.6%升高至83.8%±3.5%,LDH活性由103%±10.2%下降至68.5%±5.3%,细胞凋亡率由65.5%±4.1%下降至37.1%±2.3%(P<0.01)。100μmol H2O2预处理诱导p-AKT的表达,PI3K抑制剂ly294002阻断了H2O2预处理引起的p-AKT表达。同时ly294002拮抗了H2O2预处理诱导的抗细胞损伤和凋亡作用。结论 H2O2预处理通过PI3K途径引起AKT的活化,PI3K/AKT通路的活化介导了H2O2预处理诱导的适应性细胞保护作用。     

ERK1/2－STAT3通路在H2O2预处理导致的适应性细胞保护中的作用

目的：探讨ERK1/2-STAT3通路在H₂O₂预处理导致的适应性细胞保护中的作用。方法：在PC12细胞建立H₂O₂预处理对抗氧化应激（300 μmol/L H₂O₂）损伤细胞的模型。应用Hoechst33258核染色法观察细胞调亡的形态学改变；应用碘化丙啶(PI)染色流式细胞术检测细胞凋亡率；免疫印记法(Western blotting) 测定p-ERK1/2和p-STAT3的表达水平。结果：100 μmol/L H₂O₂预处理PC12细胞90 min可明显抑制300 μmol/L H₂O₂作用12 h引起的细胞凋亡，并激活ERK1/2和STAT3；ERK1/2抑制剂UO126和JAK2抑制剂AG-490（10 μmol/L）均可明显地阻断H₂O₂预处理引起的细胞保护作用；UO126（10 μmol/L）亦能明显地抑制H₂O₂预处理对STAT3的上调作用。结论：H₂O₂预处理能激活PC12细胞的ERK1/2-STAT3信号转导旁路，这可能是预处理的细胞保护机制之一。     

p38丝裂原活化蛋白激酶对H2O2预处理的适应性细胞保护作用的影响

3580不影响H2O2预处理的适应性细胞保护作用.50 μmol/L H2O2具有比H2O2预处理更强的激活p38的作用,H2O2预处理能明显地抑制50 μmol/LH2O2对p38的激活作用.结论 H2O2预处理抑制高浓度H2O2对p38的激活可能是其适应性细胞保护机制之一.     

p38丝裂原活化蛋白激酶对H2O2预处理的适应性细胞保护作用的影响

3580不影响H2O2预处理的适应性细胞保护作用.50 μmol/L H2O2具有比H2O2预处理更强的激活p38的作用,H2O2预处理能明显地抑制50 μmol/LH2O2对p38的激活作用.结论 H2O2预处理抑制高浓度H2O2对p38的激活可能是其适应性细胞保护机制之一.     

Survivin在过氧化氢预处理诱导的适应性细胞保护中的作用

目的探讨H2O2预处理对存活素(survivin)表达的影响及存活素在H2O2预处理的适应性细胞保护中的作用。方法在PC12细胞建立H2O2预处理对抗H2O2诱导细胞凋亡的实验模型,应用甲氮甲唑蓝(MTT)法检测细胞存活率,碘化丙啶(PI)染色流式细胞术检测细胞凋亡率,Hoechst染色检测细胞凋亡的形态学改变,免疫印迹法(Westernblot)测定存活素的表达水平。结果用100μmol/LH2O2预处理PC12细胞90min可明显地抑制300μmol/LH2O2作用12h后引起的细胞毒性和细胞凋亡,并可以显著地上调PC12细胞存活素的表达;JAK2抑制剂AG-490不仅可以抑制存活素的表达,而且拮抗H2O2预处理的适应性细胞保护作用。结论存活素是JAK-STAT通路的靶基因,可能在H2O2预处理诱导的适应性细胞保护机制中起着重要的作用。     

STAT3抑制剂Stattic激活ERK通路诱导THP-1细胞IL-8的产生及细胞凋亡

目的观察信号转导子与转录激活子3(STAT3)抑制剂Stattic对THP-1细胞产生白细胞介素8(IL-8)和细胞凋亡的影响,并探讨其机制。方法采用(0、 1、 5、 10、 15、 20)μmol/L Stattic处理THP-1细胞0、 1、 3、 6、 12、 24h,实时荧光定量PCR检测细胞IL-8、 IL-6、 IL-1β、肿瘤坏死因子α(TNF-α)的mRNA水平, ELISA检测细胞培养上清液IL-8蛋白水平,流式细胞术检测THP-1细胞的凋亡, Western blot法检测细胞STAT3、细胞外信号调节激酶(ERK)的蛋白磷酸化水平;采用(0、 1、 5、 10)μmol/L的ERK通路选择性抑制剂U0126预处理THP-1细胞,反转录PCR检测U0126对Stattic诱导THP-1细胞表达IL-8 mRNA水平的影响。结果 (10～20)μmol/LStattic显著上调IL-8在THP-1细胞中的mRNA和蛋白表达,仅(15、 20)μmol/LStattic能诱导THP-1细胞凋亡; Stattic处理THP-1细胞1、 3、 6、 12、 24 h,均显著上调IL-8的mRNA水平,以3 h时最为明显,在6 h以后呈时间依赖性上调IL-8的蛋白水平并诱导THP-1细胞凋亡;Stattic呈浓度和时间依赖性抑制STAT3磷酸化,时间依赖性地诱导ERK磷酸化,在(1、 5、 10、 15、 20)μmol/L时均显著诱导ERK磷酸化。另外, U0126显著抑制Stattic诱导的IL-8 mRNA表达。结论 STAT3抑制剂Stattic通过激活ERK信号通路诱导THP-1细胞凋亡和IL-8产生。     

JAK-STAT通路调制NF-κB介导H2O2预处理的细胞保护作用

目的：探讨核因子-кB（nuclear factor-кB, NF-кB）在H₂O₂预处理诱导的适应性细胞保护作用中的作用及JAK-STAT通路对NF-кB的调制。方法：在PC12细胞建立H₂O₂预处理对抗氧化应激（300 μmol/L H₂O₂）损伤细胞的实验模型。应用碘化丙啶（PI）染色流式细胞术检测细胞凋亡率，免疫印迹法（Western blotting）测定NF-κB和STAT3的表达水平。结果：用100 μmol/L H₂O₂预处理PC12细胞90 min可显著地抑制300 μmol/L H₂O₂作用12 h引起的细胞凋亡，并明显地上调NF-κB和STAT3的表达，NF-κB抑制剂MG-132（10 μmol/L）和JAK2抑制剂AG-490（10 μmol/L）均可抑制H₂O₂预处理引起的适应性细胞保护作用及上调NF-κB表达的作用。结论：JAK-STAT通路调节NF-кB介导的H₂O₂预处理的细胞保护作用。     

雌激素减轻H2O2诱导PCI2细胞凋亡

目的 观察雌激素对H2O2诱导细胞凋亡的作用,探讨雌激素保护作用机制.方法 在PCI2细胞建立H2O2诱导细胞凋亡的实验模型.用MTT法检测细胞存活率,比色法测定乳酸脱氢酶(LDH)活性,Hoechst染色检测细胞凋亡,碘化丙啶(PI)染色流式细胞术检测细胞凋亡率,比色法测定caspase-3活性.结果 H2O2明显降低PCI2细胞的存活率,使LDH释放增加,促进细胞凋亡,并能明显地升高caspase-3的活性.雌激素能显著地减轻上述变化.结论 雌激素对抗H2O2诱导的细胞凋亡,抑制caspase-3的激活是其细胞保护机制之一.     

An apparent KIR2DS2-negative KIR2DL2-positive genotype discloses the novel allele KIR2DS2*00104

KIR2DS2*00104 lacks a distinctive synonymous substitution of KIR2DS2 in nucleotide 418 that affects KIR genotyping.     

CaO-MgO-P_2O_5-SiO_2-CaF_2系统自硬性玻璃的研究

为研究钙离子、镁离子在体内环境中对自硬性玻璃结晶行为的影响,为自硬性生物活性玻璃的临床应用提供依据,本文设计了CaO-P2O5-SiO2-CaF2(Ca-glass)和CaO-MgO-P2O5-SiO2-CaF2(CaMg-glass)系统玻璃并使用模拟体液(simulated body flu id,SBF)进行了研究。首先采用磷酸氢二氨[(NH4)2HPO4]/[NH4H2PO4]硬化液与Ca-glass、CaMg-glass制成硬化体,然后使用X射线衍射(XRD)、扫描电镜(SEM)、失重、力学分析等方法,研究硬化体在SBF中的结晶性、降解性和力学性能。实验结果表明,玻璃粉末与磷酸铵缓冲溶液反应形成了磷酸铵钙[(NH4)2.Ca(HPO4)2.H2O]硬化体。硬化体经过SBF浸泡,Ca-glass系统硬化体中部分磷酸铵钙转化成羟基磷灰石,而CaMg-glass系统硬化体仍然为磷酸铵钙。Ca-glass与CaMg-glass硬化体在SBF中浸泡28天分别降解19.4%和31.3%,抗压强度分别为93.14MPa和64.52MPa。镁离子的歧化作用是导致Ca-glass、CaMg-glass硬化体结晶性能、降解性能以及力学性能差别的主要原因。     

K2O-B2O3-Al2O3-SiO2-MgO-F系统可切削生物微晶玻璃

目的 可切削微晶玻璃的制备温度高达1500 ℃以上,此特性严重制约其产业化发展.本文设计制备了K2O-B2O3-Al2O3-SiO2-MgO-F系统低温云母生物微晶玻璃,并探讨制备工艺对材料结构和性能的影响.方法 采用1300 ℃熔化工艺与600～750 ℃晶化热处理工艺制备微晶玻璃,通过X射线衍射分析方法研究微晶玻璃的晶相组成,利用扫描电子显微镜观察微晶玻璃的形貌,并通过显微硬度分析、高速砂轮切削实验考察微晶玻璃的可切削性能.结果 分别经过600 ℃、650 ℃、700 ℃、750 ℃晶化热处理2 h、4 h、8 h后,玻璃中均形成了主晶相为氟金云母的微晶玻璃,微晶玻璃的显微硬度为3～8 GPa.且随着晶化温度的升高,微晶玻璃层状结构逐渐明晰,但硬度不断下降,其可切削性持续提高.结论 低温下熔化K2O-B2O3-Al2O3-SiO2-MgO系统玻璃工艺降低了可切削微晶玻璃的制备温度和成本,利于产业化生产和推广应用.     

Cross-Protection in Mice After Immunization with H2N2, H3N2, and Heq2Neq2 Influenza Virus Strains

Mice were vaccinated with the influenza viruses A/Japan/57 (H2N2), A/Hong Kong/68 (H3N2), and A/Equi/Miami/63 (Heq2Neq2) and the hemagglutinin and neuraminidase recombinants derived from these viruses. After infection with the parent viruses, protection was compared with serological findings. It was found that influenza vaccine protects not only against infection with a strain identical or closely related to the vaccine strain, but against heterologous strains as well. Vaccination with Hong Kong/68 and its neuraminidase recombinant resulted in a heterologous neuraminidase inhibition titer against Japan/57 and in a protection against infection with Japan/57. By contrast, after vaccination with Japan/57 and its neuraminidase recombinant, no relevant heterologous neuraminidase inhibition titer against Hong Kong/68 was observed, whereas a protection against infection with Hong Kong/68 did exist. A cross-protection between Hong Kong/68 and Miami/63, but no relationship in the hemagglutination or neuraminidase inhibition tests, was established in the preinfection sera. A one-way antigenic relationship between these viruses was confirmed by the rise of hemagglutinin or neuraminidase antibodies against Hong Kong/68 in the postinfection sera. No cross-protection or serological relationship existed between Miami/63 and Japan/57. Besides the hemagglutinin and neuraminidase, a third factor, the “mouse-protecting antigen,” was considered to contribute to the protection obtained. According to the protection observed, the mouse-protecting antigen of Hong Kong/68 virus is related to that of Japan/57 as well as Miami/63 virus. The mouse-protecting antigens of both Japan/57 and Miami/63 are related to that of Hong Kong/68.     

2-Perbromomethyl-2-oxazoline: a novel trifunctional initiator for the ring-opening polymerization of 2-methyl-2-oxazoline

Polymerization of 2-methyl-2-oxazoline was carried out using a trifunctional initiator, 2-perbromomethyl-2-oxazoline. The degree of polymerization (DP) of the resulting polymer was very close to the feed mole ratio of the monomer to initiator. The number-average molecular weight M?_n increased linearly with conversion, indicating the living nature of the propagating chain end. ¹H NMR and end-group analyses results are consistent with the proposal that the polymer possesses a star-shaped structure.     

H2O2 enhances Ca2+ release from osteoblast internal stores

The physiological activity of osteoblasts is known to be closely related to increased intracellular Ca2+ activity ([Ca2+]i) in osteoblasts. The cellular regulation of [Ca2+]i in osteoblasts is mediated by Ca2+ movements associated with Ca2+ release from intracellular Ca2+ stores, and transmembrane Ca2+ influx via Na+-Ca2+ exchanger, and Ca2+ ATPase. Reactive oxygen species, such as H2O2, play an important role in the regulation of cellular functions, and act as signaling molecules or toxins in cells. In this study, we investigated the effects of H2O2 on cellular Ca2+ regulation in osteoblasts by measuring intracellular Ca2+ activities using cellular calcium imaging techniques. Osteoblasts were isolated from the femurs and tibias of neonatal rats, and cultured for 7 days. The cultured osteoblasts were loaded with a Ca2+-sensitive fluorescent dye, Fura-2, and fluorescence images were monitored using a cooled CCD camera, and subsequently analyzed using image analyzing software. The results obtained are as follows: (1) The osteoblasts with lower basal Ca2+ activities yielded a transient Ca2+ increase, a Ca2+ spike, while osteoblasts with higher basal Ca2+ activities showed a continuous increase in [Ca2+]i leading to cell death. (2) Ca2+ spikes, generated after removing Na+ from superfusing solutions, were blocked by H2O2 and this was followed by a sustained increase in Ca2+ activity. (3) ATP- induced Ca2+ spikes were inhibited by pretreating with H2O2 and this was followed by a continuous increase of [Ca2+]i. When cells were pretreated with the exogenous nitric oxide (NO) donor S-Nitroso-N-acetylpenicilance (SNAP, 50 microM), treatments of ATP (1 mM) induced a Ca2+ spike-like increase, but [Ca2+]i did not return to the basal level. (4) The expression of inositol- 1,4,5-triphosphate receptor (IP3R) was enhanced by H2O2. Our results suggest that H2O2 modulates intracellular Ca2+ activity in osteoblasts by increasing Ca2+ release from the intracellular Ca2+ stores.     

13C NMR spectroscopy of 2-formamido-2-methylpropyl acrylate and poly(2-formamido-2-methylpropyl acrylate)

The synthesis and characterization of 2-formamido-2-methylpropyl acrylate (FMPA) is reported. ¹³C NMR spectra of FMPA in CDCl₃, CD₃OD, DMSO-d₆, DMF-d₇, and D₂O exhibit two pairs of lines for all seven carbon atoms at room temperature; the ratio of the two conformers varies moderately with solvent (21 : 79 to 41 : 59). The conformers are believed to involve strong internal hydrogen bonding which is not completely broken even by the addition of trifluoroacetic acid to CDCl₃ (1/1, v/v). However, the pairs of lines coalesce in turn as the temperature is raised to 120°C in DMSO-d₆. FMPA was polymerized at 35°C in DMF and CHCl₃, using a free radical initiator and the polymer was characterized by ¹³C NMR spectroscopy.     

KIR2DL2/S2 and KIR2DS5 in alcoholic cirrhotic patients undergoing liver transplantation

IntroductionThe molecular mechanisms underlying alcoholic liver fibrosis and cirrhosis are not completely understood. Hepatic fibrosis involves the interplay of diverse cells and factors, including hepatic stellate cells (HSCs), Kupffer, NK cells, and T-lymphocyte subsets. Killer-cell immunoglobulin-like receptors (KIR) are membrane receptors involved in mediation between NK and activated HSCs, regulating NK cell function through their interaction with HLA-I molecules. The aim of this study was to analyse the genetic association between KIR genes and the susceptibility to or protection from alcoholic cirrhosis (AC) in a cohort of male AC patients undergoing liver transplantation (LT) with and without concomitant viral infections.Material and methodsKIR genotyping was performed in nuclear DNA extracted from 281 AC patients and compared with 319 male controls.ResultsSignificant differences between total AC patients and healthy controls were only found in the case of KIR2DL2 and KIR2DS5. KIR2DL2 was significantly underrepresented in non-viral AC patients (52.6% vs. 63.3%; p = 0.015), while patients heterozygous for KIR2DL2 were also underrepresented in the non-viral AC group compared with controls (p = 0.034). KIR2DS5 was overrepresented in this group compared with healthy controls (p = 0.002). All these observations were only evident in AC patients older than 54 years old.ConclusionsOur data suggest a contrary effect of KIR2DL2 and KIR2DS5 in AC patients older than 54 years, in whom the presence of KIR2DL2 appears to be protective against AC, whereas the presence of KIR2DS5 seems to promote the fibrotic process, particularly in patients with no associated viral infection.     

ExspiratorischepO2-undpCO2-Kurven bei Atmung von N2-, He- und Ar−O2-Gemischen

Zusammenfassung Zur Untersuchung der intrapulmonalen Gasmischung wurden an zehn Versuchspersonen die exspiratorischenpO₂- undpCO₂-Kurven fortlaufend und simultan massenspektrometrisch in Abhängigkeit vom Atemvolumen bei Atmung von Stickstoff-Sauerstoff-, Helium-Sauerstoff- und Argon-Sauerstoff-Gemischen registriert.Im Mischluftanteil wurden für den Abfall despO₂ von 75% auf 25% der Endamplitude im Mittel bei N₂–O₂-Atmung 81,6 ml, bei He–O₂-Atmung 66,1 ml und bei Ar–O₂-Atmung 71,9 ml benötigt. Die entsprechenden Zahlen für den Anstieg despCO₂ sind bei Atmung von N₂–O₂ 84,9 ml, von He–O₂ 68,5 ml und von Ar–O₂ 80.6 ml.DerpO₂ des Alveolarluftanteils sank während der letzten 300 ml Exspirationsvolumen bei Atmung des N₂–O₂-Gemisches im Mittel um 4,7 Torr, bei He–O₂ um 3,4 Torr und bei Ar–O₂ um 6,8 Torr. DerpCO₂ stieg gleichzeitig im Mittel bei Atmung des N₂–O₂-Gemisches um 2,8 Torr, bei He–O₂ um 2,1 Torr und bei Ar–O₂ um 3,7 Torr.Die Ursachen dieser Differenzen werden für den Mischluftanteil auf unterschiedliche Diffusions- und Strömungsbedingungen in den zentralen Lungenabschnitten zurückgeführt. Demgegenüber lassen sich die unterschiedlichen Partialdruckänderungen im Alveolarplateau durch Diffusion in den peripheren Lungenabschnitten und durch die Form der O₂ und CO₂-Bindungskurven erklären.Mit finanzieller Unterstützung der Europäischen Gemeinschaft für Kohle und Stahl durchgeführte Forschungsarbeit.