Alteration of NF-kB and TNF-α mRNA and protein in hippocampus in the chronic constrictive injury model of rats

Objective To investigate the alteration of nuclear factor kappa B( NF-κB) and tumor necrosis factor-a (TNF-α) mRNA and protein in hippocampus in chronic constrictive injury (CCI) model of rats. Methods Seventy-six male Wistar rats were randomly divided into 2 groups ( n = 38): the CCI group which received the chronic constriction injury and the sham group which received the sham operation as control. The mechanical and thermal nociceptive thresholds were assessed with paw withdrawal latency (PWL) to von Frey filaments and radiant heat at 1d before and ld,4d,7d,14d and 28d after CCI operation. Five animals were sacrificed at each time point for real-time polymerase chain reaction (real-time PCR) and another three animals sacrificed at 7d postoperation for immunofluorescence histochemical staining. Results The thresholds to mechanical and thermal stimuli decreased obviously after operation in CCI group. The expressions of TNF-α and NF-κB mRNA began to increase at ld( (2.079 ±0. 104)times and 4d( ( 1.640 ± 0.064) times) after operation and reached the peak at 7d ((2.748 ±0.147)times, (2.010 ±0.096)times) ,then the expressions of TNF-a mRNA began to decrease,while the expressions of NF-kB mRNA maintained at a high level throughout the experiment. The result of immunofluorescence histochemical staining revealed that NF-kB and TNF-α protein expressions at 7 day increased significantly on the hippocampus,which was consisted with NF-κB and TNF-a mRNA levels. Conclusion The activation NF-κB and TNF-α in hippocampus may be involved in the procession of neuropathic pain.     

神经病理性疼痛大鼠脊髓背角NF-κB及其下游肿瘤坏死因子α表达的变化

目的 观察大鼠脊髓背角中NF-κB及其下游肿瘤坏死因子α(TNF-α)在慢性坐骨神经挤压性损伤(CCI)疼痛模型中表达的变化规律.方法 雄性SD大鼠76只,随机分为手术组(CCI组)和假手术组(Sham组)(n=38),于CCI前1 d、CCI后1、4、7、14、21、28 d各时间点测定机械痛阈及热痛阈后立即处死大鼠,取腰髓,采用实时荧光定量PCR和免疫荧光双标的方法分别测定NF-κB和TNF-α的mRNA含情和蛋白表达变化.结果 CCI组大鼠手术侧机械痛阈及热痛阈明显降低,脊髓背角中NF-κB水平和TNF-α的表达增加,明显高于对侧和假手术组;NF-κB和TNF-α的mRNA水平于CCI后4 d开始增加,分别为术前的(1.20±0.16,2.32±0.27)倍,7 d达到高峰,为术前的(1.75±0.20,3.38±0.41)倍,随后TNF-α迅速下降,而NF-κB于CCI后28 d仍为术前的(1.15±0.24)倍,维持于较高水平(P＜0.05).术后第7天的免疫荧光双标显示NF-κB和TNF-α在术侧脊髓后角存在共定位表达.结论 CCI致大鼠脊髓背角NF-κB活化并上调TNF-α的表达,参与神经病理性疼痛的调控过程.     

Effects of Propofol on The mRNA Expression of Toll-like Receptor 4 in BV-2 Cells During Mimic Ischemia-Reperfusion Injury In Vitro

This study investigated the effects of propofol on the mRNA expression of Toll-like receptor-4 (TLR4) in BV-2 cells during mimic ischemia-reperfusion (I/R) injury in vitro. BV-2 cells, a mouse microglia line, were cultured and divided into 4 groups at random: control group (group C), ischemia/reperfusion group (group I/R), low-dose propofol (25 μmol/L) intervention group (group PF25) and high-dose propofol (100 μmol/L) intervention group (group PF100). The mRNA expression of TLR4 and NF-κB was measured by means of RT-PCR. TNF-α levels in the supernatants of BV-2 cells were detected by ELISA. The results showed that the mRNA expression of TLR4 and NF-κB was significantly higher in groups I/R, PF25 and PF100 than in group C (P<0.01). And the TNF-α level in the supernatants was elevated in groups I/R, PF25 and PF100 as compared with that in group C (P<0.01). After pre-treatment with propofol, the mRNA expressions of TLR4 and NF-κB and the TNF-α level were significantly decreased in groups PF25 and PF100 in comparison to those in group I/R (P<0.01). And the decrease in those indicators was more significant in group PF100 than in group PF25 (P<0.01). It was concluded that propofol exerted brain-protecting effects during I/R injury by suppressing the mRNA expressions of TLR4 and NF-κB and deceasing the TNF-α level.     

The Role of IκBα in TNF-α-induced Apoptosis in Hepatic Stellate Cell Line HSC-T6

To investigate the role of NF-κB in TNF-α induced apoptosis in HSC-T6, a mutant IκBα was transfected into HSC-T6 cells by lipofectin transfection technique and its transient effect was examined 48 h after the transfection. The activation of NF-κB was detected by immune fluorescence cytochemistry and Western blotting with anti-p65 antibody. The apoptosis and the rate of inhibition by TNF-α in both transfected and untransfected HSC-T6 cells were measured respectively by FAC-Scan side scatter analysis and MTF methods. Our results showed that TNF-α could activate NF-κB in untransfected cells but not in transfected HSC-T6 cells. The percentage of apoptosis in transfected cells were significantly higher than that in the untransfected ones （P〈0.01） and it was also true of the inhibition rate （P〈0.01）. It is concluded that the resistance of HSC-T6 towards apoptosis induced by TNF-α can be mediated by NF-κB activation. The inhibition of NF-κB activation by mutant IκBα can attenuate the resistance of HSC-T6 cells and increase its sensitivity to TNF-α.     

Inhibition of NF-κB by mutant IκBα enhances TNF-α-induced apoptosis in HL-60 cells by controlling bcl-xL expression

Backgound The aim of this study was to explore whether the inhibition of nuclear factor-κB (NF-κB)activation by mutant IκBα (S32,36→A) can enhance TNF-α-induced apoptosis of leukemia cells and to investigate the possible mechanism. Methods The mutant IκBα gene was transfected into HL-60 cells by liposome-mediated techniques. G418 resistant clones stably expressing mutant IκBα were obtained by the limiting dilution method. TNF-α-induced NF-κB activation was measured by electrophoretic mobility shift assay (EMSA). The expression of bcl-xL was detected by RT-PCR and Western blot after 4 hours exposure of parental HL-60 and transfected HL-60 cells to a variety of concentrations of TNF-α. The percentage of apoptotic leukemia cells was evaluated by flow cytometry (FCM). Results Mutant IκBα protein was confirmed to exist by Western blot. The results of EMSA showed that NF-κB activation by TNF-α in HL-60 cells was induced in a dose-dependent manner, but was almost completely inhibited by mutant IκBα repressor in transfected cells. The levels of bcl-xL mRNA and protein in HL-60 cells increased after exposure to TNF-α, but changed very little in transfected HL-60 cells. The inhibition of NF-κB activation by mutant IκBα enhanced TNF-α-induced apoptosis. Thecytotoxic effects of TNF-α were amplified in a time- and dose-dependent manner. Conclusions NF-κB activation plays an important role in the resistance to TNF-α-induced apoptosis. The inhibition of NF-κB by mutant IκBα could provide a new approach that may enhance the antileukemia effects of TNF-α or even of other cytotoxic agents.     

Characteristics of lymphocyte nuclear factor-κB signal transduction kinase expression in aging process and regulatory effect of epimedium flavonoids

Objective:To study the characteristics of lymphocyte nuclear factor kappa B(NF-κB) signal transduction kinase-related molecular mRNA differential expressions at various month age segments in aging process and the intervening effect of Epimedium flavonoids(EF) on it.Methods:Sixty SD rats were divided into six groups,according to animals’ age,i.e.,the 3 days(d) group,the 4 months(m) group,the 10 m group,the 18 m group,the 27 m group,and the 27 m+EF group.RNA was extracted from separated splenic lymphocytes. Adopting NF-κB signal path functional genome oligonucleotide gene-chip(128 related genes),the integral characteristics and differences of NF-κB signal transduction kinase-related mRNA expressions were determined, and the intervening effect of EF was examined.Results:The mean level of the NF-κB signal transduction kinase-related mRNA expressions in rats’ splenic lymphocytes lowered with aging;the highest expression was presented at 3 d after birth,and then,it lowered gradually,with the lowest level at 18 m or 27 m.After EF intervention,the expression level was raised to the 10-18 m level in the aged rats.Conclusion:The changing rules of lymphocyte NF-κB-signal-transduction-kinase-related mRNA expressions in various stages of aging are helpful for selecting the well time for preventing and intervening aging,and will also give a hint to the molecular index for assessment of senility retarding researches.     

Effects of propofol on the mRNA expression of toll-like receptor 4 in BV-2 cells during mimic ischemia-reperfusion injury <Emphasis Type="Italic">in vitro</Emphasis>

This study investigated the effects of propofol on the mRNA expression of Toll-like receptor-4 （TLR4） in BV-2 cells during mimic ischemia-reperfusion （I/R） injury in vitro. BV-2 cells, a mouse microglia line, were cultured and divided into 4 groups at random： control group （group C）, ischemia/reperfusion group （group I/R）, low-dose propofol （25 μmol/L） intervention group （group PF25） and high-dose propofol （100 μmol/L） intervention group （group PF100）. The mRNA expression of TLR4 and NF-κB was measured by means of RT-PCR. TNF-α levels in the supernatants of BV-2 cells were detected by ELISA. The results showed that the mRNA expression of TLR4 and NF-κB was significantly higher in groups I/R, PF25 and PF100 than in group C （P〈0.01）. And the TNF-α level in the supernatants was elevated in groups I/R, PF25 and PF100 as compared with that in group C （P〈0.01）. After pre-treatment with propofol, the mRNA expressions of TLR4 and NF-κB and the TNF-α level were significantly decreased in groups PF25 and PF100 in comparison to those in group I/R （P〈0.01）. And the decrease in those indicators was more significant in group PF100 than in group PF25 （P〈0.01）. It was concluded that propofol exerted brain-protecting effects during I/R injury by suppressing the mRNA expressions of TLR4 and NF-κB and deceasing the TNF-α level.     

Effect of N-tosyl-L-phenylalanylchloromethyl Ketone on Tumor Necrosis Factor-alpha -induced NF-κB Activation and Apoptosis in U937 Cell Line

Summary: To investigate the effect of N-tosyl-L-phenylalanylchloromethyl ketone (TPCK) on tumor necrosis factor-alpha-induced NF-κB activation and apoptosis in U937 cell line, changes and subcellular localization of NF-κB/p65 and IκB-α were observed by fluorescencemicroscopy and expression and degradation of IκB-α by flow cytometry. The apoptosis of U937 cells was measured by flow cytometry and electrophoresis of DNA. Immunolfluorescence assay showed that NF-κB/p65,IκB-α only localized in cytoplasm. After TNF-α stimulation, p65 was localized only in nuclei, and IκB-α was only localized in cytoplasm and decreased. The changes of TNF-α stimulation were specifically inhibited by TPCK. Flow cytometry also revealed the downregulation of IκB-α protein during TNF-α-induced apoptosis and the down-regulation was specifically inhibited by TPCK. Flow cytometry also showed the apoptosis of U937 cells after TNF-α induction. DNA ladder can be detected in cells treated by TNF-α. It is concluded that degradation of IκB-α protein and NF-κB/p65 translocation occur during TNF-α-induced apoptosis of U937 cells, suggesting the activation of NF-κB.TPCK-sensitive protease plays an important role in the degradation of IκB-α protein induced by TNF-α in U937 cells. TPCK sensitive protease also plays an important role in the apoptosis of U937 cells induced by TNF-α.     

Role of liver X receptors alpha agonist on expressions of LPS-induced inflammatory response associated factor IRAK-4 and NF-kappaB in Kupffer cells

Objective： To explore the role of activated liver X receptor α （LXRα） on the expressions of interleukin-1 receptor associated kinase-4 （IRAK-4） and NF-kappaB （NF-κB） in the inflammatory response which induced by LPS in the Kupffer cells and to investigate the possible mechanisms of LXRα negative regulation of inflammatory response. Methods： The Kupffer cells were isolated from male Kunming mice by collagen perfusion in situ. And these cells were divided into 4 groups： normal control group, LPS treatment group, LXRct agonist T0901317 treatment group, LPS and T0901317 combined treatment group. The LPS treatment group were treated with a final concentration of 1 μg/ml LPS in RPMI 1640 and cultured for 6 h, the T0901317 treatment group were treated with a final concentration of 5 μg/ml in RPMI 1640 and cultured for 24 h, and the combined treatment group received pre-culture for 24 h with a final concentration of 1μg/ml T0901317 in RPMI 1640 and then cultured for 6 h with a final concentration of 5 μg/ml LPS in RPMI 1640. All groups were cultured for 30 h. The expression of LXRα, IRAK-4 and NF-κB at mRNA and protein levels were detected by real-time PCR and Western blotting, and the TNF-α and IL-1β levels were detected by ELISA. Results： The levels of LXRα mRNA and protein were highest in T0901317 group, and lowest in LPS group （P〈0.05）. The level of IRAK4 and NF-κB mRNAs and proteins were evidently lower in the Combined-treated group than in LPS group （P〈0.05）. And the level of TNF-α and IL-1 were observed highest in LPS group （P〈0.05）, but no difference among the Control group, T0901317 group and Combined-treated group （P〉0.05）. Conclusion： These date suggest that the LXR agonists can effectively up-regulate the expressions of LXRα mRNA and protein and inhibit the inflammatory response. This may be via down-regulating the expressions of IRAK4 and NF-κB at mRNA and protein levels.     

Triptolide-induced apoptosis by inactivating nuclear factor-kappa B apoptotic pathway in multiple myeloma <Emphasis Type="Italic">in vitro</Emphasis>

The effect of triptolide on proliferation and apoptosis of human multiple myeloma RPMI-8226 cells in vitro,as well as the roles of nuclear factor-kappa B(NF-κB) and IκBα was investigated.The effect of tritptolide on the growth of RPMI-8226 cells was studied by MTT assay.Apoptosis was detected by Hoechest 33258 staining and Annexin V/PI double staining assay.The expression of NF-κB and IκBα was observed by Western blot and confocal microscopy.The results showed that triptolide inactivated NF-κB apoptotic pathway in human multiple myeloma RPMI-8226 cells.Triptolide at nM range induced proliferation inhibition in a dose-and time-dependent manner and apoptosis in a dose-dependent fashion in RPMI-8226 cells.Besides,we observed the inhibition of NF-κB /p65 in the nuclear fraction was correlated with the increase in the protein expression of IκBα in the cytosol.These results suggested that triptolide might exhibit its strong anti-tumor effects via inactivation of NF-κB/p65 and IκBα.     

GMCSF对高氧暴露新生大鼠肺组织RAGE-NF-κB通路的影响

目的 探讨高氧暴露对新生大鼠肺组织高级糖基化终产物受体(RAGE)-核因子κB(NF-κB)信号通路的影响及粒细胞巨噬细胞集落刺激因子(GMCSF)肺损伤保护作用的相关机制.方法 24只3日龄新生大鼠随机平均分为3组:正常对照组(空气环境下7 d)、高氧对照组(95%氧暴露7 d)、高氧干预组(95%氧暴露7 d+GMCSF皮下注射9 μg/kg/次,共3次);光镜观察并盲法进行肺组织病理学损伤评分;RT-PCR法检测肺组织匀浆RAGE mRNA、NF-κB mRNA表达;Western印迹检测肺组织匀浆RAGE、NF-κB蛋白表达;ELISA检测支气管肺泡灌洗液(BALF)及血清中肿瘤坏死因子-α(TNF-α)水平;免疫组化法检测肺组织石蜡切片RAGE表达情况.结果 正常对照组、高氧对照组、高氧干预组肺组织损伤评分分别为0.46±0.20、3.06±0.33、2.31±0.56,差异有统计学意义(P=0.000);3组RAGE mRNA和蛋白表达分别为0.14±0.02、0.34±0.06、0.28±0.04和0.30±0.04、0.76±0.11、0.55±0.08,差异均有统计学意义(均P=0.000);3组NF-κB mRNA和蛋白表达分别为0.41±0.21、0.90±0.36、0.69±0.30和0.41±0.26、0.96±0.43、0.77±0.33,差异均有统计学意义(P=0.000和P=0.017);3组BALF中TNF-α水平分别为76±10、224±42、143±24,差异有统计学意义(P=0.000).以上各指标结果在高氧对照组、高氧干预组均明显高于正常对照组(均P<0.05),高氧干预组低于高氧对照组(P<0.05).3组血清TNF-α水平差异无统计学意义(P>0.05).结论 GMCSF可能通过下调RAGE-NF-κB信号通路对高氧肺损伤发挥保护作用.

Abstract：

Objective To explore the effects of granulocyte-macrophage colony-stimulating factor (GMCSF) on hyperoxia exposure lung injury in newborn rats and elucidate its protective mechanism of operating via the signaling pathway of advanced glycation end products (RAGE)-NF-κB.Methods Twenty-four 3-day-old SD rats from 3 litters were randomly divided into 3 groups. They were hyperoxia exposure plus GMCSF group (group A), hyperoxia exposure group (group B) and air exposure group (group C). The rats from groups A and B were placed in a sealed Plexiglas chamber with a minimal in-and-outflow, providing 6-7 exchanges per hour of chamber volume and maintaining O2 levels above 95%.While the rats in group C only were exposed to air simultaneously.The rats in group A received subcutaneous injections of recombinant murine GMCSF (9 μg/kg) during hyperoxia exposure at 24 h, 72 h and 120 h respectively. And the rats in groups B and C received subcutaneous injections of saline vehicle alone at the same time point. Seven days later, all were sacrificed and immunohistochemistry was employed to assess the expression of RAGE in lung tissue. The levels of tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF) and serum samples were detected by ELISA (enzyme-linked immunosorbent assay). The RAGE mRNA and NF-κB mRNA in tissue homogenates were detected by RT-PCR while RAGE and NF-κB by Western blot. Also the values of lung damage score were calculated with microscopic histology.Results The value of lung damage score in group C, B and A was 0.46±0.20, 3.06±0.33 and 2.31±0.56 respectively, there was significantly difference among three groups (P=0.000). The expression of RAGE mRNA and protein in three groups were 0.14±0.02, 0.34±0.06, 0.28±0.04 and 0.30±0.04, 0.76±0.11, 0.55±0.08 respectively. There were both significantly differences among three groups (P=0.000, P=0.000). The expression of NF-κB mRNA and protein in three groups were 0.41±0.21, 0.90±0.36, 0.69±0.30 and 0.41±0.26, 0.96±0.43, 0.77±0.33 respectively, there were both significantly difference among three groups (P=0.000, P=0.017). The level of TNF-α in BALF was 76±10, 224±42 and 143±24 respectively, there was significantly difference among three groups (P=0.000). All indicators above in group B and group A were significantly more than those in group C (all P<0.05), while these indicators in group A were lower than those in group B. But there was no difference in the level of TNF-α of serum among three groups (P>0.05).Conclusion GMCSF may protect hyperoxia-induced lung injury via down-regulating the signaling pathway of RAGE-NF-κB.     

Effect of surfactant protein A on lipopolysaccharide-induced tumor necrosis factor-α expression in human proximal tubular epithelial cells

Background Surfactant protein A （SP-A） contributes to the regulation of sepsis-induced acute lung injury.In a previous study,we demonstrated the expression and localization of SP-A in the kidneys.The present study evaluated the effect of SP-A on lipopolysaccharide （LPS）-induced tumor necrosis factor-α （TNF-α） expression and its underlying mechanisms in the human renal tubular epithelial （HK-2） cells.Methods Indirect immunofiuorescence assay was used to detect SP-A distribution and expression in HK-2 cells.HK-2 cells were treated with various concentrations of LPS （0,0.1,1,2,5,and 10 mg/L） for 8 hours and with 5 mg/L LPS for different times （0,2,4,8,16,and 24 hours） to determine the effects of LPS on SP-A and TNF-α expression.Then,HK-2 cells were transfected with SP-A siRNA to analyze nuclear factor κB （NF-κB） P65 and TNF-α expression of HK-2 cells after LPS-treatment.Results Indirect immunofluorescence assay revealed that SP-A is localized to the membrane and cytoplasm of HK-2 cells.Interestingly,SP-A1/SP-A2 and TNF-α expression were found to be significantly increased in HK-2 cells upon LPS treatment.Transfection of LPS-treated HK-2 cells with SP-A siRNA resulted in significant increases in the levels of NF-κB P65 protein and TNF-α mRNA and protein compared to those in non-transfected LPS-treated HK-2 cells.Conclusion SP-A plays an important role in protecting cells against sepsis-induced acute kidney injury by inhibiting NF-κB activity to modulate LPS-induced increase in TNF-α expression.     

Fuzheng Huayu Formula (扶正化瘀方) Prevents Rat Renal Interstitial Fibrosis Induced by HgCl2 via Antioxidative Stress and Down-regulation of Nuclear Factor-Kappa B Activity

Objective: To investigate the mechanism of action of Fuzheng Huayu Formula (扶正化瘀方, FZHY) against renal interstitial fibrosis (RIF) relating to oxidative injury and nuclear factor-kappa B (NF-κB) activity. Methods: Thirty-two Sprague-Dawley rats were randomly divided into 3 groups: normal group, model group and FZHY treatment group. The RIF model was induced by oral administration of HgCl2 at a dose of 8 mg/kg body weight once a day for 9 weeks. Meanwhile, rats in FZHY treatment group orally took FZHY at a dose of 4.0 g/kg rat weight for 9 weeks. The content of hydroxyproline (Hyp) and collagen deposition in kidney were observed. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), the content of glutathione (GSH) and malondialdehyde (MDA) of kidney were tested. The expressions of inhibitor-κappa B (IκB), phospho-IκB (p-IκB), tumor necrosis factor-α (TNF-α), matrix metalloproteinase-2 (MMP-2) and α-smooth muscle actin (α-SMA) were analyzed by Western blot. α-SMA expression was also observed by immunofluorescent staining. MMP-2 activity was measured by gelatin zymography. NF-κB activation was determined by electrophoretic mobility shift assay. Results: Renal interstitial fibrosis was induced by HgCl2, demonstrated by remarkably increased Hyp contents and excessive collagen deposition in kidney (P<0.01). FZHY significantly inhibited renal interstitial collagen deposition and reduced Hyp content of the HgCl2-treated rats (P<0.01). GSH content decreased obviously, and MDA content increased significantly in HgCl2-treated rats compared with that of normal rats (P<0.01). FZHY significantly increased GSH content and decreased MDA content in the model rats (P<0.01). The expression α-SMA was increased in model rats compared with that of normal rats, FZHY significantly decreased its expression (P<0.01). The expressions of p-IκB and TNF-α and MMP-2, MMP-2 activity, and NF-κB activation were increased in model group compared with that in normal group (P<0.01), FZHY significantly decreased NF-κB activation, MMP-2 activity and p-IκB and TNF-α expressions (P<0.01). Conclusions: FZHY could protect kidney from oxidative injury intoxicated by HgCl2, and antagonized oxidative stress-stimulated NF-κB activity through inhibition of IκB phosphorylation in the interstitial fibrotic kidney, these effects importantly contributed to FZHY action mechanism against renal interstitial fibrosis.     

Effects of beating-heart and arrested heart intracardiac procedure on the inflammation induced by cardiopulmonary bypass

Objective：To evaluate the effects of beating-heart and arrested heart intracardiac procedure on the expression of tumor necrosis factor alpha （TNF-α mRNA in myocardium. Methods： Thirty congenital ventricular septal defect （VSD） patients aged from 5 to 10 years old were randomly divided into 2 groups equally. Group A underwent traditional arrested heart intracardiac procedures ; group B underwent beating-heart procedures. Specimens of myocardium were obtained at the onset （baseline） and the end of cardiopulmonary bypass （CPB） for the determination of TNF a mRNA. Concentration of TNF-α was respectively measured after anesthetic induction （T1）, 20 min after the beginning of CPB （T2）, at the end of CPB （T3） and 6, 12, 24 h after CPB （T4-6） in all patierits： After separating polymorphonuclear leucocyte （PMN）, we distilled nuclear protein and mensurated the activation of nuclear factor-κB （NF-κB） by elec-trophoretic mobility shift assay （EMSA）. Results ：Compared with baseline, the expression of TNF-κ mRNA significantly increased in both groups （P〈0. 05）. TNF-α mRNA level of group A was significantly higher than that of group B at the end of CPB （P〈0.05）. The plasma concentration of TNF-α and neutrophil NF-κB activity in group A was significantly higher than that of group B at T,4-6（P〈0.05）. Conclusion：Compared with traditional arrested CPB, beating heart intracadiac procedure can effectively reduce the expression and release of TNF-α; it will benefit the protection of pediatric myocardial during CPB.     

The role of NF-κB in hepatocellular carcinoma cell

Objective To evaluate the role of nuclear factor-kappaB (NF-κB) and IκBα in hepatocellular cacinoma (HCC) SMMC7721 cells, the consequence of NF-κB inhibition in SMMC7721 cells transfected with mutated IκBα (mIκBα) plasmid and the effect of stable inhibition of NF-κB activity in combination with Doxorubicin.Methods Western blot was used to determine the expression of NF-κB and IκBα in SMMC7721 cells and normal liver cells. Nuclear protein was used to evaluate the binding of the 32P-labeled tandem κB sequence using electrophoretic mobility shift assay and the expression of NF-κB using Western blot between SMMC7721 cells transfected with mIκBα plasmid (SMMC7721-MT) and control cells. Furthermore, cell viability was plotted between SMMC7721-MT and control cells. The binding of κB sequence and cell viability between SMMC7721-MT and control cells at different concentrations of Doxorubicin were also investigated.Results Western blot analysis for nuclear extract showed more P50 (NF-κB1) and P65 (RelA) expression in SMMC7721 cells compared with normal liver cells. The expression of cytosolic IκBα protein in SMMC7721 cells was less than that in normal cells. SMMC7721-MT cells inhibited NF-κB nuclear translocation at 0, 24, 48 and 96 hours. Furthermore, NF-κB cannot be detected in the nuclear protein of SMMC7721-MT cells by Western blot. By calculating cell viability, the proliferation of SMMC7721-MT cells was shown to be suppressed more significantly than that of control cells. NF-κB in untransfected cells was activated by Doxorubicin in a dose-dependent manner, but that in SMMC7721-MT cells was not induced at low concentrations of Doxorubicin. Compared with untransfected cells, the viability of SMMC7721-MT cells was significantly suppressed at the same concentration of Doxorubicin (P&lt;0.01）.Conclusions The present study demonstrates that upregulation of NF-κB and downregulation of inhibitory kappaB (IκBα) in SMMC7721 cells are related with the growth of hepatocellular cacinoma cells. Stable expression of mIκBα in SMMC7721-MT cells can inhibit NF-κB nuclear translocation and suppress cell growth. Furthermore, stable inhibition of NF-κB activity in combination with Doxorubicin can significantly inhibit cell proliferation in SMMC7721-MT cells. Thus, modulation of NF-κB may represent an improvement in the efficacy of HCC therapies and be worthy of further research and investigation.     

Effect of cefodizime on cytokines expression in mouse neutrophils and its related mechanism

Objective： To explore the regulating effects of cefodizime on cytokines expression of neutrophil response to Klebsiella pneumoniae （Kle. p） treatment. Methods： We detected the types and expression of cytokines secreted by neutrophils by cDNA array and RT-PCR. We also analyzed the changes of signal transduction in this process by detecting the expression of toll like receptor 4 （TLR4） and the inhibitor factor of κBα （I-κBα） expressed by neutrophils. The activity of NF-κB DNA-binding in neutrophils was measured by electrophoretic mobility shift assay （EMSA）. Results： Cefodizime increased the neutrophils production of TNF-α, IL-β3 and the mRNA expression of TLR4 in the early stage of Kle. p stimulation in mice, which seemed corresponding to the enhanced NF-κB DNA-binding activity. Conclusion： Cefodizime regulates the cytokines expression of neutrophils through the LPS-TLR4-NF-κB pathway by affecting the expression of TLR4 mRNA and the DNA binding activities of NF-κB in mice with the challenge of Kle. p.     

EFFECT OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ACTIVATORS ON TUMOR NECROSIS FACTOR-αL EXPRESSION IN NEONATAL RAT CARDIAC MYOCYTES A

Objecfive To investigate the effect ofperoxisome proliferator-αctivated receptor-α (PPARα) and PPARγ activators on tumor necrosis factor-α (TNFα) expression in neonatal rat cardiac myocytes. Primary cultures of cardiac myocytes from 1- to 3-dayold Wistar rats were prepared, and myocytes were ex-posed to lipopolysaccharide (LPS) and varying concentrations of PPARα or PPARγ activator (fenofibrate or pioglitazone).RT-PCR and ELISA were used to measure TNFα, PPARα, and PPARγ expression in cultured cardiac myocytes. Transient transfection of TNFα promoter with or without nuclear factor-kappaB (NF-κB) binding site to cardiac myocytes was performed. Performed Pretreatment of cardiac myocytes with fenofibrate or pioglitazone inhibited LPS-induced TNFα mRNA and protein expression in a dose-dependent manner. However, no significant changes were observed on PPARα or PPARα mRNA expression when cardiac myocytes were pretreated with fenofibrate or pioglitazone. Proportional suppression of TNFα promoter activity was observed when myocytes was transiently transfected with whole length of TNFα promoter (-721/ 17) after being stimulated with LPS and fenofibrate or pioglitazone, whereas no change of promoter activity was observed with transfection of TNFα reporter construct in deletion of NF-κBbinding site (- 182/ 17). Conchusions PPARα and PPARγ activators may inhibit cardiac TNFα expression but not accompanied by change of PPARα or PPARγ mRNA expression. Therefore PPARα and PPARγ activators appear to play a role in anti-inflammation.The mechanism may partly be involved in suppression of the NF-κBpathway.