小白菊内酯抑制紫杉醇诱导的肿瘤细胞凋亡

目的　探讨NF κB在紫杉醇诱导肿瘤细胞凋亡中的作用及小白菊内酯对紫杉醇诱导凋亡的影响。方法　以人乳癌BCap37细胞和人表皮KB细胞为研究对象 ,用 5,1 0和 2 0 μmol·L-1 小白菊内酯预处理细胞 ,以DNA凋亡梯状条带、DNA含量、MTT、细胞甩片及电泳迁移率变动分析 (EMSA)法检测它对紫杉醇诱导细胞凋亡的影响并探索其作用靶点。结果　通过检测DNA凋亡梯状条带、DNA含量和细胞生存率 ,2 0μmol·L-1 小白菊内酯能显著抑制紫杉醇所诱导的BCap37和KB细胞凋亡 ,但不影响紫杉醇诱导肿瘤细胞G2 /M期阻滞。EMSA实验表明小白菊内酯能抑制紫杉醇诱导激活NF κB。结论　小白菊内酯通过抑制NF κB的激活来抑制紫杉醇所诱导的肿瘤细胞凋亡 ,而紫杉醇诱导肿瘤细胞凋亡的过程可能与G2 /M期阻滞无关     

Effects of Huogu I Formula (活骨I方) on correlated factors of bone regeneration in chickens with steroid-induced necrosis of femoral head

Objective:To study the mechanism of HuoguⅠFormula（活骨Ⅰ方） in treating osteonecrosis of femoral head.Methods:Forty-eight healthy female Leghorn chickens were randomly divided into control group,model group and HuoguⅠgroup,and each group consisted of 16 chickens.At the meantime of model establishment,chickens of the HuoguⅠgroup were administrated with decoction,while the model and control group with distilled water by gavage.At the 8th and 16th week after medication,blood samples were obtained for blood lipid detection while both sides of femoral head were harvested for the rest of examinations.Specifically, expressions of bone morphogenetic protein-2（BMP2）,transforming growth factor betal（TGFβ₁）,Smad4 and Smad7 were evaluated by immunohistochemistry,while expression of osteoprotegerin/receptor activator of nuclear factor kappaB ligand（OPG/RANKL） mRNA was detected by in situ hybridization.Results:Compared with the control group,serum levels of total cholesterol（TC）,triglyceride（TG） and low-density lipoprotein cholesterol （LDL-C） in the model group rose significantly.Positive cell counting of BMP2,TGFβ₁,Smad4 and OPG in femoral head of the model group dropped prominently.Positive cell counting of Smad7 and RANKL increased dramatically. In contrast with the model group,levels of TC,TG and LDL-C in Huogu I group reduced significantly.Positive cell counting of BMP2,TGFβ₁,Smad4 and OPG in femoral head of the Huogu I group increased prominently. Indices of Smad7 and RANKL both decreased significantly.Especially at the 8th week,these variations were more significant.Conclusion:HuoguⅠFormula is effective in promoting repair of necrotic femoral head by regulating the expressions of BMP2,TGFβ₁,Smads and OPG/RANKL of osteoclast in femoral head.     

Insulin-like growth factor-binding protein-3 suppresses tumor growth via activation of caspase-dependent apoptosis and cross-talk with NF-κB signaling

Nuclear factor-kappaB (NF-κB) is constitutively activated in a variety of human cancers including prostate cancer and involved in tumorigenesis, tumor progression and chemo-resistance. Insulin-like growth factor-binding protein-3 (IGFBP-3) is a potent tumor suppressor and is significantly suppressed in a variety of cancers. Diverse biological effects of IGFBP-3 have been reported to be both dependent and independent of the IGF/IGF-I receptor (IGF-IR) axis. The precise underlying mechanisms of IGF/IGF-IR-independent, antiproliferative actions of IGFBP-3 are yet to be elucidated. We found an inverse correlation between NF-κB activity and IGFBP-3 expression during prostate cancer progression using an in vitro prostate cancer progression model. Restoration of IGFBP-3 resulted in significant inhibition of constitutively elevated NF-κB activity in prostate cancer cells. IGFBP-3 further inhibited the expression of NF-κB-regulated angiogenic factors such as VEGF and IL-8, and cell adhesion molecules, ICAM-1 and VCAM-1. This inhibitory action of IGFBP-3 was IGF/IGF-IR-independent since IGFBP-3 mutant devoid of IGF binding affinity had a similar inhibitory effect. We identified that IGFBP-3 degrades the key NF-κB regulatory molecules-IκBα and p65-NF-κB proteins through activation of caspase-8 and -3/-7, thereby inhibiting elevated NF-κB activity in prostate cancer. Finally intratumoral administration of IGFBP-3 resulted in significant tumor suppression as well as sensitization of antitumor effect of doxorubicin. Our findings indicate that IGFBP-3 exerts antitumor effects via IGF-independent mechanisms which involve activation of caspase-dependent apoptosis and cross-talk with NF-κB signaling. The use of IGFBP-3 as a cancer therapeutic with this distinctive suppression mechanism may offer alternate means to treat chemotherapy resistant tumors.     

Berberine suppresses amyloid-beta-induced inflammatory response in microglia by inhibiting nuclear factor-kappaB and mitogen-activated protein kinase signalling pathways

Objectives The neuroinflammation induced by amyloid-beta peptide (Aβ) is one of the key events in Alzheimer's disease (AD) progress in which microglia are the main cells involved. Berberine, one of the major constituents of Chinese herb Rhizoma coptidis, is known for its anti-inflammatory, anti-oxidative and anti-microbial activity. In this study, we examined the effects and possible underlying mechanisms of berberine in Aβ-induced neuroinflammation using murine primary microglia cells and cultured BV2 microglia cells. Methods The effects of berberine on Aβ-stimulated inflammatory factor expression and secretion were examined using RT-PCR and ELISA analysis. The signal pathways involved in berberine's effects were also investigated using Western blot and immunofluorescence analysis. Results In primary microglial and BV2 cells, berberine treatment significantly inhibited Aβ-stimulated production of interleukin-6 and monocyte chemotactic protein-1. Berberine treatment down-regulated the expression of cyclo-oxygenase-2 and induced nitric oxide synthase in these cells. Moreover, berberine strongly inhibited the nuclear factor-kappaB (NF-κB) activation, presumably through blocking the phosphoinositide 3-kinase/protein kinase B and mitogen-activated protein kinase signalling pathways. Conclusions Our data indicated berberine is a potent suppressor of neuroflammation, presumably through inhibition of NF-κB activation, and suggested berberine has therapeutic potential for the treatment of neuroinflammation that is involved in neurological diseases such as AD.     

胃癌中NF-кB与COX-2表达的研究

目的探讨NF-кB、COX-2的表达与胃癌的关系及临床意义。方法采用免疫组织化学方法(S-P法)对胃癌组织、正常胃黏膜中NF-кB p65及COX-2蛋白表达进行检测。结果 NF-кB p65蛋白和COX-2蛋白在胃癌组织中的阳性表达率分别为67%和60%,正常胃黏膜中的阳性表达率分别为21%和18%,2者比较均有显著性差异(P均<0.01)。在低分化组的阳性表达率分别为79%和72%,高/中分化组的阳性表达率分别为53%和47%,2者比较均有显著性差异(P均<0.05);在浸润深度为T3+T4组的阳性表达率分别为73%和66%,T1+T2组的阳性表达率分别为22%和22%,2者比较均有显著性差异(P<0.01);在临床Ⅲ～Ⅳ期组的阳性表达率分别为78%和74%,Ⅰ～Ⅱ期组的阳性表达率分别为48%和37%,2者比较均有显著性差异(P均<0.01)。不同性别、年龄、肿瘤部位及大体分型胃癌组织中NF-кB p65和COX-2蛋白的表达无显著性差异(P均>0.05)。胃癌组织中NF-кB p65和COX-2蛋白的表达呈明显正相关(rs=0.539,P<0.01)。结论胃癌组织中的NF-кB和COX-2表达增高,提示其与胃癌的发生、发展、侵袭、淋巴转移密切相关。     

还原型谷胱甘肽对肝缺血再灌注损伤核因子-κB影响的实验研究

 目的探讨核因子-κB在肝缺血再灌注损伤中的表达和还原型谷胱甘肽的保护作用.方法将90只健康家兔随机分为对照组、肝缺血再灌注组和还原型谷胱甘肽保护组,制备肝缺血再灌注损伤模型.观察三组肝组织中核因子-κB的表达、血清ALT、丙二醛(MDA)及血浆TNF-α含量和肝脏的病理变化.结果正常肝组织中仅偶见肝细胞核因子-κB的表达,肝缺血再灌注损伤时,核因子-κB的表达明显增强,ALT、MDA、TNF-α含量显著升高(P＜0.01),肝脏出现坏死,大量炎性细胞浸润;使用还原型谷胱甘肽后,上述指标的异常变化均明显减轻,其差异有显著性意义(P＜0.01或P＜0.05).结论核因子-κB参与了肝缺血再灌注损伤,还原型谷胱甘肽能抑制其表达,对肝缺血再灌注损伤有积极的保护作用.     

檞皮素对大鼠酒精性脂肪肝核转录因子表达的影响

目的:探讨檞皮素对大鼠酒精性脂肪肝的防治作用及其可能机制。方法:wistaur(?)鼠48只,随机分为:正常对照、酒精性脂肪肝模型、檞皮素处理、纳洛酮处理4组,实验4 wk末,处死所有大鼠,检测血AST,ALT和TNF-α,并行肝脏病理组织学及核转录因子(NF-ΚB)表达的检测。结果:檞皮素和纳洛酮组血AST,ALT和TNF-α明显低于模型组(檞皮素组:150.7±23.6 U/L,57.4±8.4 U/L,0.83±0.27μg/L;纳洛酮组:148.3±21.4 U/L,55.2±7.3 U/L,0.85±0.34μg/L vs 205.0±31.5 U/L,70.5±9.2 U/L,4.08±1.23μg/L;P<0.05),而高于正常对照组(127.6±17.8 U/L,47.9±7.1 U/L,0.22±0.10μg/L;P<0.05).檞皮素和纳洛酮组肝脏脂肪变程度较模型组轻,且懈皮素组肝内NF-ΚB表达水平显著低于模型组(60.27个/HP vs 28.49个/HP,P<0.05)。结论:檞皮素可能通过抑制NF-ΚB及TNF-α的表达,发挥防治酒精性脂肪肝的作用.     

Melatonin inhibits the expression of the inducible isoform of nitric oxide synthase and nuclear factor kappa B activation in rat skeletal muscle

This study investigated whether the induction of inducible nitric oxide synthase (iNOS) produced by acute exercise in rat skeletal muscle could be prevented by melatonin and whether iNOS down-regulation was related to inhibition of nuclear factor kappaB (NF-kappaB) activation. Male Wistar rats received melatonin i.p. at a dose of 1.0 mg/kg body weight 30 min before being exercised for 60 min on a treadmill at a speed of 25 m/min and a 10% slope. Exercise caused a significant induction of iNOS protein levels and a marked activation of NF-kappaB that were significantly prevented in rats treated with melatonin. Exercise also resulted in increased IkappaB kinasealpha (IKKalpha) and phosphorylated IkappaBalpha protein levels, whereas IkappaBalpha content decreased. These effects were blocked by melatonin administration. The increase in the muscle concentration of thiobarbituric acid reactive substances and in the oxidized/reduced glutathione ratio induced by exercise was partially prevented by melatonin. Our data indicate that melatonin has potent protective effects against damage caused by acute exercise in rat muscle, preventing oxidative stress, NF-kappaB activation and iNOS over-expression. These findings support the view that melatonin treatment, by abolishing the IKK/NF-kappaB signal transduction pathway, might block the production of noxious mediators involved in the inflammatory process.