NFAT2 is implicated in corticosterone-induced rat Leydig cell apoptosis

Aim： To investigate the activation of the nuclear factor of activated T cells （NFAT） and its function in the corticosterone （CORT）-induced apoptosis of rat Leydig cells. Methods： NFAT in rat Leydig cells was detected by Western blotting and immunohistochemical staining. Cyclosporin A （CsA） was used to evaluate potential involvement of NFAT in the CORT-induced apoptosis of Leydig cells. Intracellular Ca^2＋ was monitored in CORT-treated Leydig cells using Fluo-3/AM. After the Leydig cells were incubated with either CORT or CORT plus CsA for 12 h, the levels of NFAT2 in the nuclei and in the cytoplasm were measured by semi-quantitative Western blotting. The role of NFAT2 in CORT- induced Leydig cell apoptosis was further evaluated by observing the effects of NFAT2 overexpression and the inhibition of NFAT2 activation by CsA on FasL expression and apoptosis. Results： We found that NFAT2 was the predominant isoform in Leydig cells. CsA blocked the CORT-induced apoptosis of the Leydig cells. The intracellular Ca^2＋ level in the Leydig cells was significantly increased after the CORT treatment. The CORT increased the level of NFAT2 in the nuclei and decreased its level in the cytoplasm. CsA blocked the CORT-induced nuclear translocation of NFAT2 in the Leydig cells. Both CORT-induced apoptosis and FasL expression in the rat Leydig cells were enhanced by the overexpression of NFAT2 and antagonized by CsA. Conclusion： NFAT2 was activated in CORT-induced Leydig cell apoptosis. The effects of NFAT2 overexpression and the inhibition of NFAT2 activation suggest that NFAT2 may potentially play a pro-apoptotic role in CORT-induced Leydig cell apoptosis through the up-regulation of FasL.     

皮质酮诱导的Leydig细胞凋亡中Egr的表达及其作用

目的评价皮质酮是否通过活化钙调神经磷酸酶（CaN）来诱导Leydig细胞中转录因子Egr-2及Egr-3的表达及两种Egr对皮质酮诱导的Leydig细胞凋亡的影响。方法采用RT-PCR方法检测CaN的抑制剂环孢菌素A（CsA）对经皮质酮处理的Leydig细胞中Egr-2及Egr-3的mRNA表达水平；用Annexin-V-FITC和PI双标法评价Egr-2和Egr-3的表达载体对Leydig细胞凋亡率的影响。结果皮质酮能诱导Leydig细胞中Egr-2及Egr-3的表达，且该诱导作用可被CsA抑制；过量表达的Egr-2及Egr-3均可使经皮质酮诱导的Leydig细胞凋亡率增加，并以Egr-3的作用较为显著。结论高浓度的皮质酮可通过活化CaN诱导Leydig细胞中Egr．2和Egr．3的表达，两种Egr对经皮质酮诱导的Leydig细胞的凋亡均具有促进作用。     

皮质酮诱导大鼠Leydig细胞凋亡是一经caspase-3激活的过程

目的 超生理剂量的皮质酮(大鼠体内的糖皮质激素)能诱导大鼠Leydig细胞凋亡。但有关皮质酮诱导Leydig细胞凋亡的细胞内机制尚不清楚。本研究旨在观察皮质酮是否经caspase-3激活的途径诱导大鼠Leydig细胞凋亡。方法 采用Western Blot方法检测不同时间点上经皮质酮处理的大鼠Leydig细胞中caspase-3酶原及裂解的caspase-3酶表达情况。运用荧光发光法检测不同时间点上经皮质酮处理的人鼠Leydig细胞中caspase-3酶活性。结果 caspase-3酶原表达水平在皮质酮处理6h时开始上升，12h及24h时表达量下降，而具生物活性的、裂解的caspase-3酶于12h时开始出现，24h时的表达水平最为显著。caspase-3酶活性在皮质酮处理12h时明显升高，以24h时最为显著。Caspase-3抑制剂DEVD-CHO对经皮质酮处理12、24及48h的Leydig细胞中的caspase-3酶活性均具有明显的抑制作用，加caspase-3抑制剂的处理组其细胞基因组DNA电泳未见有凋亡特征性的梯状条带。结论 皮质酮诱导的大鼠Leydig细胞凋亡是一经caspase-3激活的过程。     

NF-кB抑制剂PDTC联合阿霉素对肝癌HepG2细胞增殖的影响

目的 探讨核转录因子-кB ( NF-кB)抑制剂毗咯烷二硫氨基甲酸(PDTC)与阿霉素(ADM)联合应用对抑制HepG-2 细胞增殖的效应及其机制.方法 培养人肝癌HepG-2 细胞株,分为空白组,ADM组、PDTC组、PDTC+ADM组,观察HepG-2 细胞的生长情况,MTT比色法检测细胞增殖,利用中效原理判定药...     

Erratum

To evaluate the effect of estrogen and androgen levels on erythrocyte deformability in endocrinological erectile dysfunction patients. Methods: The estrogen level, androgen level, IR of 30 psychogenic and 15 endocriological ED were studied and the correlation between the estrogen and androgen levels and RI were analyzed. Results: There is a negative correlation between the androgen and estrogen levels and IR;     

皮质酮诱导的大鼠Leydig细胞凋亡中caspase-3活化途径的研究

目的我们新近的研究表明，超生理剂量的皮质酮（大鼠体内的糖皮质激素）可通过激活caspase-3诱导大鼠Leydig细胞凋亡。本研究拟评价在皮质酮诱导的大鼠Leydig细胞凋亡过程中，caspase-3的激活是否有其上游的caspase-8平和 caspase-9的参与。方法采用荧光分光光度法榆测经皮质酮处理的大鼠Leydig细胞中caspase-8活性，以DNA梯状电泳条带作为评价细胞凋亡的指标，观察caspase-8抑制剂是否能够抑制细胞凋亡，采用RTPCR枪测皮质酮诱导的大鼠Leydig细胞中caspase-9的mRNA水平。结果在皮质酮诱导的大鼠Leydig细胞中出现caspase-8活性增高，以12h最为址著，升高的caspase-8的活性可被caspase-8抑制剂抑制，并导致Leydig细胞的凋亡过程被阻断。Leydig细胞中caspase-9的mRNA水平在皮质酮作用下上升，同样以12h最为显著。结论皮质酮诱导的大鼠Leydig细胞调亡与caspase-8和caspase-9有关。     

Nuclear factor kappaB protects pancreatic beta-cells from tumor necrosis factor-alpha-mediated apoptosis

Recent studies incriminating tumor necrosis factor (TNF)-alpha as the final effector in pancreatic beta-cell death in type 1 diabetes underscore the potential role of TNF-alpha-dependent NF-kappaB activation as an important modulator of pancreatic beta-cell death in autoimmune diabetes. Although nuclear factor (NF)-kappaB activation has been implicated in the protection of target cells against apoptosis by a variety of death effectors, its role in pancreatic islet cell death is not clear. We studied the role of NF-kappaB activation in pancreatic islet cell death by using a gamma-interferon (IFN-gamma)/TNF-alpha synergism model we had previously reported. TNF-alpha induced inhibitor of kappaB (IkappaB) degradation and p65 translocation from cytoplasm to nuclei in MIN6N8 insulinoma cells. The NF-kappaB DNA-binding nuclear complex activated by TNF-alpha contained both the p65 and p50 subunit. IFN-gamma pretreatment did not affect TNF-alpha-induced NF-kappaB activation. Treatment with a proteasome inhibitor blocked p65 translocation and induced susceptibility to TNF-alpha in otherwise resistant insulinoma cells or primary pancreatic islet cells. Specific inhibition of NF-kappaB activation by adenoviral transduction of IkappaB "superrepressor" also sensitized insulinoma cells and primary islet beta-cells to TNF-alpha-induced apoptosis. These results suggest the protective role of NF-kappaB activation against cytokine-mediated pancreatic beta-cell death, contrary to previous reports implicating NF-kappaB as a mediator of pancreatic islet cell death.     

NF-κB、Caspase-3在腺苷诱导人HepG2细胞凋亡中的作用

目的 研究NF-κB、Caspase-3在腺苷(ADO)体外诱导人肝癌HepG2细胞凋亡中的作用.方法 将不同浓度的ADO(0.1～5 mmol/L)作用于HepG2细胞,采用MTT法测定ADO抑制细胞增殖的时间效应和剂量效应.2.0 mmol/L ADO单用或联合NF-κB抑制剂吡咯烷二硫氨基甲酸(PDTC,100 μmol/L)作用HepG2细胞12 h、24 h,采用Hoechst 33342荧光染色法及流式细胞术(FCM)观察细胞凋亡及细胞周期,Western blot技术检测NF-κB蛋白表达;荧光比色法测定Caspase-3酶活性.结果 ADO对HepG2细胞生长具有显著抑制作用,并呈一定的量效和时效关系.药物作用24 h、48 h的IC50分别为2.52 mmol/L和1.89 mmol/L.ADO单独处理HepG2细胞12 h和24 h或联合PDTC处理后,细胞凋亡率分别为8.30%、22.32%;20.18%、30.89%,均显著高于对照组(0.81%,P<0.001);ADO作用HepG2细胞后荧光显微镜观察到细胞凋亡的形态学改变,FCM分析药物处理组显示典型特征性的亚二倍体凋亡峰(sub-G1),细胞生长周期阻滞于G0/G1期;同时伴有Caspase-3活性显著升高(P<0.05).ADO处理后显著增加了NF-κB蛋白表达(P<0.05);PDTC有效抑制了NF-κB表达,同时增加了 Caspase-3活性及ADO的细胞毒作用(P<0.05).结论 ADO诱导了HepG2细胞凋亡并活化Caspase-3.抑制NF-κB活性可通过Caspase-3途径增强ADO的细胞毒作用.     

核因子-κB活化受抑对TRAIL诱导前列腺癌细胞株PC-3M凋亡效能的影响

目的 观察二硫代氨基甲酸毗咯烷(PDTC)对核因子(NF)-κB活化的抑制作用,探讨PDTC对肿瘤坏死因子相关凋亡诱导配体(TRAIL)诱导激素耐受型前列腺癌细胞株PC-3M凋亡的促进作用.方法 根据单用TRAIL(25、50、100 μg/L)或PDTC(25、50、100μmoL/L)或两者合用[25/25、25/50、25/100、50/25、50/50 PDTC(μmoL/L),TRAIL(μg/L)]等不同干预情况将PC-3M细胞分组,以细胞免疫组织化学和凝胶电泳迁移率(EMSA)检测法分析NF-κB核转位的活化情况,并通过MTY和流式细胞分选法研究PDYTC的参与对TRAIL诱导凋亡能力的影响.结果 EMSA和细胞免疫组织化学结果显示TRAIL单独诱导PC-3M细胞凋亡过程中引起NF-κB的显著活化,但是经PDTC预处理的PC-3M细胞中NF-κB的核转位受到抑制.导致其对细胞凋亡的保护作用丧失.检测凋亡显示PDTC作为NF-κB的强抑制物本身并不具有明显的细胞毒性,TRAIL+PDTC作用组的杀伤效应显著增强,远远超过单用TRAIL组对细胞的杀伤率(P<0.01).结论 TRAIL杀伤激素耐受型前列腺癌细胞的作用受到NF-κB活化的影响,抑制NF-κB活化可以显著增强TRAIL的凋亡诱导效用.     

Pyrrolidine dithiocarbamate exerts anti-proliferative and pro-apoptotic effects in renal cell carcinoma cell lines.

BACKGROUND: The activation of nuclear factor-kappaB (NF-kappaB) has been implicated in the development, progression and metastasis of renal cell carcinoma (RCC). This study investigates the effect of pyrrolidine dithiocarbamate (PDTC), a NF-kappaB inhibitor, on two metastatic human RCC cell lines, ACHN and SN12K1. METHODS: RCC cell lines and normal cells were exposed to 25 or 50 microM of PDTC. Apoptosis was measured by flow cytometry and TdT-mediated nick end labelling methods. Cell viability and proliferation were measured by MTT and BrdU assays, respectively. Expression of NF-kappaB subunits, IkappaBs, IkappaB Kinase (IKK) complex and apoptotic regulatory proteins were analysed by western blotting and/or immunofluorescence. DNA-binding activity of NF-kappaB subunits were measured by ELISA. RESULTS: RCC cell lines had a higher basal level expression of all the five subunits of NF-kappaB than normal primary cultures of human proximal tubular epithelial cells or HK-2 cells. PDTC decreased the viability and proliferation of RCC, but not normal cells. Of the two RCC cell lines, ACHN had a higher basal level expression of all the five NF-kappaB subunits than SN12K1 and was more resistant to PDTC. While PDTC induced an overall decrease in expression of all the five NF-kappaB subunits in both RCC cell lines, unexpectedly, it increased the nuclear expression of NF-kappaB in ACHN, but not in SN12K1. PDTC reduced the DNA-binding activity of all the NF-kappaB subunits and the expression of the IKK complex (IKK-alpha, IKK-beta and IKK-gamma) and the inhibitory units IkappaB-alpha and IkappaB-beta. PDTC induced a significant increase in apoptosis in both RCC cell lines. This was associated with a decrease in expression of the anti-apoptotic proteins, Bcl-2 and Bcl-(XL), without marked changes in the pro-apoptotic protein Bax. CONCLUSION: These data suggest that PDTC has the potential to be an anticancer agent in some forms of RCC.     

Pyrrolidine dithiocarbamate provides protection against hypothermic preservation and transplantation injury in the rat liver: the role of heme oxygenase-1

BACKGROUND: Pyrrolidine dithiocarbamate (PDTC) represents a class of antioxidants and is a potent inducer of the heme oxygenase-1 (HO-1) gene and an inhibitor of nuclear factor-kappa B (NF-kappa B). We examined the impact of PDTC preconditioning against cold ischemia and reperfusion injury in the rat liver. METHODS: Lewis rats were treated subcutaneously with saline or PDTC solution 24 hours before harvesting. Some animals pretreated with PDTC were also given zinc protoporphyrin IX intravenously immediately after reperfusion. HO-1 expression and enzyme activity in liver tissues were analyzed at different time points after each treatment. After transplantation of 24-hour preserved livers, serum levels of transaminases and gene expression of tumor necrosis factor-alpha, interleukin-1 beta, and NF-kappa B were measured. Animal survival and cellular viability were monitored. RESULTS: HO-1 gene expression and protein synthesis were enhanced in PDTC-treated livers, leading to increased enzyme activity (P <.05). The PDTC treatment group showed lower transaminase levels (P <.05), lower cytokine and NF-kappa B messenger RNA expression (P <.05), and fewer nonviable cells (P <.05) than did the control group, whereas these PDTC effects were abolished with zinc protoporphyrin injection after reperfusion (P <.05). The best animal survival rate was observed in the PDTC group (P <.05). CONCLUSION: PDTC preconditioning reduces inflammatory responses during reperfusion. PDTC appears to exert this protective effect by induction of an antioxidative stress protein and inhibition of proinflammatory cytokines.     

Increased expression of NF-kappa B subunits in human pancreatic cancer cells

BACKGROUND: Activation of NF-kappa B-dependent antiapoptotic genes may factor in the chemoresistance of pancreatic cancer. It is not known whether NF-kappa B subunit composition changes during oncogenesis and regulates overall NF-kappa B activation. We compared the relative expression of NF-kappa B subunits with nuclear activation of p65 between variably differentiated pancreatic cancer cells. MATERIALS AND METHODS: Proliferating human pancreatic cancer cells (PANC-1, BxPC-3) and nonmalignant intestinal cells (FHS 74 Int) were harvested. Baseline expression of NF-kappa B subunits (p65, p52, p50, c-Rel) and its inhibitor I kappa B-alpha were determined by Western blot. Nuclear NF-kappa B p65 activity was measured by ELISA. Results were analyzed by ANOVA (P < 0.05) and Tukey's HSD for pairwise comparisons when appropriate (P < 0.05). RESULTS: Constitutive expression of NF-kappa B subunits was detected in proliferating, intestinal cells (FHS 74 Int). Both cytoplasmic (I kappa B-alpha, p50, p52, p65) and nuclear (p50, p52, p65, c-Rel) NF-kappa B subunits were significantly increased in both PANC-1 and BxPC-3 cells compared to FHS 74 Int. While nuclear p65 subunit levels were similarly elevated, actual p65 activity was only significantly greater in PANC-1 cells compared to either BxPC-3 or FHS 74 Int (P < 0.05). CONCLUSIONS: Compared to nonmalignant proliferating intestinal cells, these pancreatic cancer cell lines have increased levels of NF-kappa B subunits. Actual nuclear NF-kappa B activity, however, appears to correlate more with degree of tumor differentiation than with NF-kappa B subunit expression.     

吗啡对小鼠脑微血管内皮细胞P-糖蛋白表达的影响

目的 评价吗啡对小鼠脑微血管内皮细胞P-糖蛋白(P-gp)表达的影响.方法 小鼠脑微血管内皮细胞b.End3,培养于RPMI 1640无血清高糖培养基中,接种于10 cm培养皿中,分为3组,每组9皿,每皿2 ml,M组加入1 μg/ml吗啡,P+M组在加人吗啡前1 h加入5 μnol/L NF-κB抑制剂吡咯二硫氨基甲酸酯,药物浓度均为终浓度,C组不作药物处理.加入吗啡后24 h时收集细胞,测定P-gp和NF-κB p65-abcb1b DNA复合体的表达水平.结果 与C组比较,M组P-gp和NF-κB p65-abcb1bDNA复合体的表达水平上调(P＜0.01);与M组比较,P+M组P-gp和NF-κB p65-abcb1b DNA复合体的表达水平下调(P＜0.05或0.01).结论 吗啡可上调小鼠脑微血管内皮细胞P-gp表达,其机制与NF-κB介导的P-gp基因abcb1b激活有关.     

皮质酮诱导青春期大鼠睾丸间质细胞凋亡的研究

本研究目的旨在观察皮质酮能否诱导青春期大鼠睾丸间质细胞凋亡,用皮质酮分别经体内、外途径处理大鼠睾丸间质细胞。凋亡细胞经碘化丙碇（ＰＩ）标记后用流式细胞仪检测。体外研究结果表明,经１００ｎＭ皮质酮处理２４小时后的睾丸间质细胞,其凋亡量（３６．５％）显著高于对照组（１２．７％。Ｐ〈０．０１）。在体研究得到类似结果,经皮质酮（２．５ｍｇ／１００ｇ体重）处理２４小时后的大鼠,其纯化的睾丸间质细胞调亡量（２     

核因子κB在烧伤血清诱导内皮细胞细胞间黏附分子1表达中的作用

目的探讨核因子κB(NF-κB)在烧伤血清诱导内皮细胞(EC)分泌细胞间黏附分子(ICAM)1中的作用。方法人脐静脉内皮细胞(HUVEC)培养后,分别用正常人血清(对照组)、烧伤患者血清(烧伤血清组)、吡咯烷二硫代氨基甲酸盐(PDTC)+烧伤患者血清(PDTC组)刺激。于刺激0.5、1.0、2.0、4．0 b时采用电泳迁移率分析法测定HUVEC NF-κB的活性;流式细胞术检测刺激3．0、6.0、12．0、24．0 h时HUVEC膜表面ICAM-1的表达。结果刺激后烧伤血清组、PDTC组细胞NF-κB活性均明显高于对照组(P<0．01),1．0 h时达峰值[(21.03±4．87)、(7.44±0．60)×104积分灰度值],以后逐渐降低;PDTC组明显低于烧伤血清组(P<0.01)。刺激后烧伤血清组、PDTC组ICAM-1的表达均增加,刺激12．0 h吋达峰值(平均荧光密度各为327±37、142±31),与对照组比较,差异有统计学意义(P<0．01);PDTC组刺激12．0、24．0 h时低于烧伤血清组(P<0．01)。结论烧伤血清通过活化NF-κB,从而启动EC对黏附分子的合成和释放,提示NF-κB在烧伤血清诱导EC分泌黏附分子过程中起重要作用。     

Inhibition of 11beta-hydroxysteroid dehydrogenase enzymatic activities by glycyrrhetinic acid in vivo supports direct glucocorticoid-mediated suppression of steroidogenesis in Leydig cells

Previous studies have suggested that glucocorticoid (GC) can directly affect testicular testosterone (T) biosynthesis by Leydig cells through a receptor-mediated mechanism. Interconversion of corticosterone (CORT), the active form in rodents, and 11-dehydroCORT, the biologically inert 11-keto form, is catalyzed by 11betaHSD1. This enzyme thus controls the intracellular concentration of active GC. We have postulated that elevated CORT levels resulting from stress exceed the Leydig cell's capacity for metabolic inactivation of CORT, resulting in suppressed T production. The present study tested whether inhibition of 11betaHSD1 in vivo, by the administration of glycyrrhetinic acid (GA), increases intracellular active GC concentration and thereby affects serum T concentration and Leydig cell T production. Adult Sprague-Dawley rats were treated with vehicle (corn oil), CORT, GA, or GA + CORT. Serum luteinizing hormone (LH), CORT, and T levels were measured, as were the steroidogenic capacities of purified Leydig cells. Twofold elevations of CORT were achieved by the administration of either CORT or GA alone, but in both cases there was no effect on serum T levels. However, when CORT and GA were administered in combination, serum CORT levels increased 3.5-fold (to 420 +/- 34 ng/mL) and serum T levels were reduced significantly (to 0.72 +/- 0.07 ng/mL; control, 2.12 +/- 0.23 ng/mL). Serum levels of LH were not affected by CORT, GA, or GA + CORT. Consistent with the reduced serum T levels following GA + CORT, steroidogenic enzyme expression and capacities were significantly reduced compared to control. These data support a role for 11betaHSD1 in modulating intracellular CORT concentrations and, in turn, for a direct effect of GC on Leydig cells in response to stress.