Hoechst 33342-induced apoptosis is associated with decreased immunoreactive topoisomerase I and topoisomerase I-DNA complex formation

Hoechst 33342, but not Hoechst 33258, induces apoptosis and inhibits topoisomerase 1 activity in vivo. Topoisomerase I relaxes superhelical DNA through a single strand breakage/rejoining reaction in which the active site tyrosine links covalently to a 3' phosphate at the break site, forming a transient intermediate called a cleavable complex. The fate of cellular topoisomerase 1 in Hoechst 33342-induced apoptosis is unknown. We analyzed the binding capacity of topoisomerase 1 to 32P-labeled plasmid pCI DNA, the immunoreactive topoisomerase 1 concentration and topoisomerase 1 activity in BC3H-1 myocytes and HL-60 cells treated with Hoechst 33342 and Hoechst 33258 by using covalent transfer of 32P radioactivity from plasmid DNA to topoisomerase 1, Western blotting and topoisomerase 1-mediated plasmid relaxation assay, respectively. Hoechst 33342, but not Hoechst 33258, induced topoisomerase 1 dysfunction in both BC3H-1 myocytes and HL-60 cells measured by (1) a decrease in the topoisomerase 1 to DNA binding capacity or cleavable complex formation; (2) a decrease in intracellular concentration of immunoreactive topoisomerase 1; and (3) an inhibition of nuclear endogenous topoisomerase 1 activity. These results suggest that destruction of immunoreactive topoisomerase 1 and topoisomerase 1-DNA complexes or cleavable complexes results in inhibition of topoisomerase 1 activity, a key step in the Hoechst 33342-induced apoptotic process.     

缺血后大鼠海马NR1 mRNA的表达及其与细胞凋亡的关系

目的：研究短暂性前脑缺血后大鼠海马NR1 mRNA的表达及其与细胞凋亡的关系。方法：以四血管阻断法建立脑缺血动物模型,采用原位杂交、TUNEL染色和图像分析等技术。结果：(1)在CA1区和CA3区,NR1 mRNA的表达于缺血后2h上升,24h达高峰,然后下降,但CA3区幅度明显较小;在齿状回,缺血后0．5～72h,表达无显著性变化,缺血后7d才显著降低。(2)TUNEL阳性细胞主要位于CAl区,于缺血后24h出现,至72h达高峰,然后有所减少。结论：大鼠短暂性前脑缺血后,NR1 mRNA的表达和细胞凋亡在海马各区存在显著性差异;提示缺血后NR1 mRNA的表达与海马的选择性易损性和缺血性细胞凋亡之间可能存在着某种联系。     

Indoor determinants of Der p 1 and Der f 1 concentrations in house dust are different

BACKGROUND: Exposure to mite allergens is a major risk factor for sensitization and the development of asthma. Der p 1 and Der f 1 content in homes and probably the proportion of both antigens is highly variable even in the same geographical area. OBJECTIVE: We investigated specific indoor determinants of Der p 1 and Der f 1 concentrations in house dust of two German cities, Erfurt and Hamburg (n = 405 homes). METHODS: Mite allergen levels were determined using monoclonal antibodies against Der p 1 and Der f 1 by the ELISA method. Indoor relative humidity and temperature were monitored continuously in the homes over 1 week. The characteristics of homes and occupants were assessed by questionnaire to obtain information on factors which may have an impact on the mite antigen concentration in house dust. These determinants were studied by multivariate regression analysis. RESULTS: The correlation between concentrations of Der p 1 and Der f 1 inside the homes was weak (r = 0.29-0.35), indicating that different determinants are relevant. Concentrations of the allergens were significantly higher on lower floors (ratios 2-8 times, Der p 1, Der f 1), on old mattresses (ratios 3-13 times, Der p 1, Der f 1), in post-war buildings (ratio 6 times, Der p 1), for non-central heating (ratio 2 times, Der p 1), for old carpets (ratio 3 times, Der p 1) and for the presence of a dog in the house (ratio 3 times, Der f 1). Furthermore, mite concentration increases with raising relative humidity (ratio 1.03 per 1%, Der p 1) and with decreasing temperature (ratio 0.86 per 1 degrees C, Der p 1) indoors. CONCLUSION: Both Der p 1 and Der f 1 concentrations should be measured in house dust, since they are only weakly correlated and have different determinants.     

坐骨神经分支选择性损伤模型L4～6背根神经节水平不同时间点P2X3mRNA表达变化

目的观察坐骨神经分支选择性损伤(SNI)动物制作型模后不同时间点L4~6背根神经节(DRG)水平P2X3mRNA的表达情况,探讨外周P2X3mRNA在神经病理性痛模型不同阶段中的作用。方法 54只健康雄性SD大鼠完全随机分为空白对照(control)组、假手术(sham surgery)组和手术(surgery)组。通过结扎腓总神经及切断胫神经,保留腓肠神经的方法建立SNI模型。动态观察造模前、造模后1d、3d、7d和14d双侧足跖机械痛阈;Real-time PCR法检测患侧造模后3d、7d和14d L4~6 DRG水平P2X3mRNA表达情况。结果模型制作后各时间点,surgery组大鼠患侧足跖痛阈明显降低(P0.05),sham surgery组大鼠与control组比较差异无显著性(P0.05);各组大鼠健侧足跖痛阈于模型制作后各时间点均无显著变化(P0.05)。模型制作后3d、7d,surgery组大鼠L4、L5、L6 DRG水平P2X3mRNA表达均有不同程度的提高(P0.05);而模型制作后14d,surgery组大鼠L5、L6DRG水平P2X3mRNA表达明显减少(P0.05),L4 DRG水平P2X3mRNA表达仍显著多于sham surgery组(P0.05)。模型制作后各时间点、各DRG水平,sham surgery组和surgery组大鼠P2X3mRNA表达差异均无显著性(P0.05)。结论外周P2X3mRNA参与SNI模型疼痛的产生和维持,且其在不同阶段发挥的作用不同。     

TGF-beta1 down-regulates Th2 development and results in decreased IL-4-induced STAT6 activation and GATA-3 expression

TGF-beta plays an important role in immune regulation in vivo and affects T cell differentiation in vitro. Here we describe how TGF-beta modulates Th2 development in vitro and investigate its mechanisms of action. TGF-beta down-regulated Th2 development of naive CD4+ Mel-14high T cells derived from the DO11.10 ovalbumin-specific TCR-transgenic mouse, and this was observed both in cultures driven with anti-CD3 and anti-CD28 and with splenic APC and antigen. TGF-beta down-regulated GATA-3 expression in developing Th2 and these cells showed a diminished IL-4-induced STAT6 activation. We found, however, that naive cells driven in Th2 conditions with TGF-beta did not show a significantly decreased STAT6 activation, suggesting that TGF-beta inhibits Th2 development via a STAT6-independent mechanism.     

Selective loss of T cell functions in different stages of HIV infection Early loss ofanti-CD3-induced T cell proliferation followed by decreased anti-CD3-induced cytotoxic T lymphocyte generation in AIDS-related complex and AIDS

To investigate the effects of persistant human immunodeficiency virus (HIV) infectionon T cell reactivity, functional properties of peripheral blood T cells from HIV-seropositive homosexual men in various stages of infection were studied. T cell activationvia CD3 resulting in proliferation and differentiation was measured in a model system independent of accessory cells, using immobilized anti-CD3 monoclonal antibodies (mAb). T cells from HIV-infected asymptomatic men had a decreased proliferative response compared to HIV-negative controls. T cells from AIDS-related complex (ARC) and AIDS patients, compared to T cells from asymptomatic HIV-infected men, had a significantly lower proliferative response to anti-CD3 mAb. This diminished response to anti-CD3 mAb was shown to be due to decreased interleukin (IL)2 productionand could be enhanced by co-stimulation with anti-CD28 mAb or by adding IL2. Anti-CD3-induced generation of cytotoxic T lymphocytes was fully intact in early infection but was severely decreased in T cells from ARC and AIDS patients. Cytotoxic activity could be restored to near normal levels after co-stimulation with either anti-CD28 mAb or IL2. Our data demonstrate a differential loss of T cell functions in the course of HIV infection which is predominantly caused by a lack of IL2 production after stimulation via the CD3/T cell receptor complex. In early HIV infection this seems to be predominantly caused by a specific loss of memory T cells. However, in later stages of infection when both naive and memory T cell subsets are depleted, resultingin a normal naive/memory T cell ratio, T cell functions further deteriorate probably due to intrinsic activation defects. These findings may be of pathogenic relevance since diminished T cell reactivity may facilitate spreading and replication of virulent HIV variants heralding development of ARC and AIDS.     

Nitric oxide synthase 1 and cyclooxygenase-2 enzymes are targets of muscarinic activation in normal and inflamed NIH3T3 cells

Objective  

Fibroblasts are sentinel cells that could serve as intermediaries in the immune reaction in the inflammatory process. In this work, we investigate the action of the muscarinic agonist carbachol (CARB) on the expression and function of nitric oxide synthase (NOS) and cyclooxygenase (COX) in fibroblasts under normal or inflammatory conditions.     

Vascular endothelial growth factor and its receptor Flk-1 are expressed in the hippocampus following entorhinal deafferentation

Vascular endothelial growth factor (VEGF) has been thought of as a mitogen that promotes proliferation of endothelial cells and as a neurotrophic factor that stimulates neurogenesis and axonal growth in both peripheral and central nervous systems. To investigate the potential involvement of VEGF in the lesion-induced reorganization in the brain, the expression changes of VEGF and its receptor Flk-1 were analyzed in the mouse hippocampus after transections of the entorhinal afferents. In situ hybridization and immunohistochemistry showed the time-dependent expression upregulation of VEGF mRNA and protein in the entorhinally denervated hippocampal stratum lacunosum-moleculare and dentate outer molecular layer, which initiated by 3 days postlesion, reached its maximum at 7-15 days postlesion, still persisted by 30 days postlesion for protein, and recovered to the normal levels at 30 days postlesion for mRNA and at 60 days postlesion for protein. Double labeling of VEGF and glial fibrillary acidic protein revealed that VEGF-expressing cells in the denervated areas were reactive astrocytes. Semi-quantitative RT-PCR analysis showed that VEGF receptor Flk-1 mRNA was also time-dependently upregulated in the deafferented hippocampus with its maximal elevation at 7-15 days postlesion while the Flt-1 mRNA levels remained unchanged at any time point we examined. Immunohistochemistry analysis also displayed the upregulation of Flk-1 protein in the denervated stratum lacunosum-moleculare and outer molecular layer with a time course similar to that of VEGF mRNA upregulation. Flk-1 receptors were found to be expressed not only by reactive astrocytes but also by neurites, which most likely belong to sprouting axons by 7 days postlesion and regrowing dendrites by 15-30 days postlesion. From these data we suggest that the spatiotemporal upregulation of VEGF and Flk-1 in the hippocampus is induced by entorhinal deafferentation and that VEGF may be involved in the structural reorganization in the deafferented hippocampus via directly or indirectly promoting neurite growth.     

Fatty acid synthase,Her2/neu,and E2F1 as prognostic markers of progression in non-muscle invasive bladder cancer

Non-muscle-invasive bladder cancer (NMIBC) is a heterogeneous disease which has an unpredictable risk of progression to muscle-invasive bladder cancer (MIBC). The selection of patients who may benefit from early radical intervention is a challenge. To define the useful prognostic markers for progression, we analyzed the immunohistochemical expression of fatty acid synthase (FASN), Her2/neu, and E2F1 in 60 cases of NMIBC who underwent TURBT and adjuvant intravesical bacillus-Calmette-Guérin (BCG). Their predicting role for tumor recurrence, progression, recurrence-free survival (RFS) and progression-free survival (PFS) was analyzed. High FASN expression was observed in 56.7% (34/60) of NMIBC cases, and FASN expression was significantly associated with the tumor size, grade, and tumor stage (p = 0.003, p < 0.001, p < 0.0001 respectively). Positive Her2/neu was noted in 18.3% (11/60) of the cases, and its expression was significantly associated with the tumor size, histologic grade, and tumor stage (p = 0.001, p = 0.002, p = 0.011 respectively). High E2F1 expression was detected in 40% of the cases, and it was associated with tumor size, histologic grade, and tumor stage (p < 0.001 for each). Analysis of follow-up period revealed that NMIBC with high FASN, positive Her2/neu, and high E2F1 expression exhibited a potent relation with tumor progression, shorter RFS, and poor PFS. Conclusions: High FASN, Her2/neu, and E2F1 are considered as adverse prognostic factors of tumor recurrence and progression in NMIBC and these patients should be followed carefully. Therefore, we suggest that FASN, Her2/neu, and E2F1 should be considered and evaluated during the selection of the appropriate management strategy for NMIBC patients.     

严重烫伤后脑内ZO-1mRNA表达变化与血脑屏障功能的关系

目的:探讨脑内ZO-1mRNA的表达水平在严重烫伤过程中的动态变化及其与血脑屏障功能的关系。方法:建立30%TBSAⅢ度烫伤模型,Sprague-Dawley大鼠随机分为正常对照组、烫伤组,其中烫伤组又分为烫伤后1、3、6、12、24h等5组,应用半定量逆转录-聚合酶链式反应(RT-PCR)检测ZO-1mRNA基因的表达水平,用化学法测定血脑屏障对伊文氏蓝的通透性,并分析二者的变化趋势。结果:严重烫伤后脑内ZO-1mRNA的表达迅速降低,其中以烫伤后3h降低最为显著。严重烫伤后脑组织内伊文氏蓝含量增高,其中以6h最为明显,大脑、小脑分别为(20±0.58)μg/g、(31.33±1.47)μg/g。结论:严重烫伤后的大脑内ZO-1mRNA的表达下降(P<0.01),伊文氏蓝的含量升高,ZO-1mRNA表达水平降低可能标志着血脑屏障的破坏。     

乳腺癌中ALDH1的表达及其与细胞凋亡、caspase-3的关系

目的探讨乳腺癌中乙醛脱氢酶1(aldehyde dehydrogenase class 1,ALDH1)的表达及其与细胞凋亡、caspase-3的关系。方法应用免疫组化SP法检测ALDH1和caspase-3在67例浸润性乳腺导管癌组织中的表达,应用TUNEL法检测组织中的细胞凋亡。结果 (1)乳腺癌组织中ALDH1阳性率为68.7%,与年龄负相关,与肿瘤直径、TNM分期正相关。caspase-3阳性率为62.7%,与组织学分级、TNM分期和ER正相关。(2)ALDH1阴性组凋亡指数(AI)=(3.45±2.77)%,高于ALDH1阳性组(1.78±1.74)%;乳腺癌中caspase-3阴性组AI=(1.58±1.51)%低于阳性组(2.74±2.49)%;ALDH1与caspase-3表达无关。结论 ALDH1参与细胞凋亡的作用机制可能与caspase-3无关,ALDH1蛋白在癌组织异常表达可能为临床治疗提供潜在的靶点。     

染锰大鼠生精细胞凋亡中caspase-3 mRNA、凋亡蛋白酶活化因子-1及多聚ADP核糖聚合酶的表达变化

目的:研究染锰诱导的大鼠生精细胞凋亡过程中,天冬氨酸特异性半胱氨酸酶-3(caspase-3)mRNA和凋亡蛋白酶活化因子-1(Apaf-1)、多聚ADP核糖聚合酶(PARP)的表达及其关系,探讨它们在生精细胞凋亡过程中的作用。方法:雄性SD大鼠,设立空白对照组、低剂量(15 mg/kg MnCl_2)和高剂量(30 mg/kg MnCl_2)组。实验组分别染锰4周和6周,空白对照组给予等容生理盐水,给药途径均为腹腔注射,TUNEL法检测生精细胞凋亡,原位杂交法和免疫组织化学法检测生精细胞caspase-3 mRNA、Apaf-1和PARP的表达。结果:与空白对照组比较,各染锰组生精细胞凋亡指数(AI)和caspase-3mRNA阳性细胞率均显著升高,Apaf-1和PARP阳性细胞率均显著降低。染锰剂量相同,6周与4周组比较,以及染锰时间相同,高剂量组与低剂量组比较,生精细胞AI和caspase-3 mRNA阳性细胞率均显著升高,Apaf-1和PARP阳性细胞率均显著降低。各组大鼠生精细胞AI与caspase-3 mRNA阳性细胞率呈正相关,与Apaf-1和PARP阳性细胞率呈负相关。结论:锰可影响大鼠生精细胞caspase-3 mRNA表达,促进Apaf-1和PARP分解,导致生精细胞凋亡,产生生殖毒性效应。     

ID1启动子的构建及其在不同细胞系中的表达

目的 观察不同细胞系中ID1启动子活性的表达的不同.方法 以大鼠的基因组DNA为模板克隆了长度为1742 bp(-1765/+88)的大鼠ID1启动子序列,将其连接到带有luciferase报告基因的PGL3-basic载体上,构建PGL3-ID1启动子序列.测序正确后,用磷酸钙共沉淀法转染大鼠骨髓间充质干细胞(mes...