Protective effects of erythropoietin pretreatment on myocardium with hypoxia／reoxygenation injury in rats

To establish the rat model with myocardial hypoxia/reoxygenation (H/R) injury, and investigate the protective effect of EPO pretreatment on the myocardium. Methods: Sixty male adult Wistar rats were randondv divided into 3 groups: control group, H/R group, and EPO group, 20 in each group. The rats in EPO group accepted injection of 5000 U/kg recombinant human erythropoietin (RHuEPO) through vein, and the other rats accepted the injection of the same volume of saline. Twenty-four hours after the injection, rats in the EPO and H/R groups were put into the hypoxia environment for 12h and then returned to the nonnoxic environment for 2 h, and then the samples of blood and myocardium were collected. Serum myocardial enzyme activity, apoptosis, ultrastructure, myocardial MDA contents, EPO receptor (EPOR) expression in cardiac myocytes and cardiac functions were tested. Results: EPOR expression was positive in cardiac myocytes of adult rat according to the result of immunohistochemitry assayng. Compared to those in H/R group, rats in EPO group presented lighter injury of myocardial ultrastructure, the reduction of serum myocardial erzyme activity, inhibition of apoptosis, the better recovery of cardiac functions, and the less production of oxygen-derived free radicals. Conclusion: Adult rat cardiac myocytes could express EPOR, and EPO pretreatment produced protective effects on myocardium with H/R injury.     

The Effects of PDTC plus Leflunomide and Cyclosporine on the NF-κB Signaling Pathway in Mouse-to-rat Cardiac Xenografts

In this study, the effects of pirrolidine dithiocarbamate （PDTC） plus leflunomide （Lef） and cyclosporine （CsA） on the NF-κB signaling pathway in mouse-to-rat cardiac xeno-transplantation models were investigated. NIH mice and Wistar rats served as donors and recipients respectively. Mouse-to-rat cardiac xenotransplantation was performed. The recipients were divided into 5 groups： group A （the control group）, group B （PDTC group）, group C （PDTC plus CsA group）, group D （PDTC plus Lef group） and group E （PDTC plus Lef and CsA group）. The expressions of IKKa/[3, NF-κB-P65, IκBct, ICAM-1 and NF-κB DNA binding activity in xenograft tissues were determined by immunohistochemistry and Western blot as well as electrophoretic mobility shift assay （EMSA）. The median survival time of cardiac xenografts in the control group, PDTC group, PDTC plus CsA group, PDTC plus Lef group and PDTC plus Lef and CsA group was （2.17±0.41）, （2.33±0.52）, （4.67±1.21）, （7.00±1.79） and （9.00±1.41） days respectively. The survival time of xenografts in the PDTC plus Lef and CsA group was significantly longer than that in other four groups （P〈0.05 for all）, that in the PDTC plus Lef group longer than that in the control group, PDTC group and PDTC plus CsA group （P〈0.05 for all）, that in PDTC plus CsA group longer than the control group and PDTC group （P〈0.05 for all）. The expressions of IKKα/β, NF-κB-P65, IκBα and ICAM-1 and NF-κ3 DNA binding activity were notably increased in mouse-to-rat cardiac xenografts. The expressions were decreased in the control group, PDTC group, PDTC plus CsA group, PDTC plus Lef and PDTC plus Lef and CsA group in turn. It was concluded that PDTC plus Lef and CsA can significantly suppress the expressions of IKKα/β, NF-κB-P65, IκBα, ICAM-1 and NF-κB DNA binding activity, thereby prolonging the survival of the cardiac xenografts.     

雌激素对缺氧/复氧神经元高迁移率族蛋白B1及核因子-κB表达的影响

目的 探讨雌激素对缺氧/复氧诱导新生大鼠皮质神经元损伤的保护作用及其机制.方法 将培养7 d的大鼠皮质神经元随机分为三组,A组为正常对照组,B组采用缺氧/复氧(H/R),C组采用雌激素(17βE2)预处理加H/R处理,各组在H/R后0、1、3、6、12、24 h各时间点,以TUNEL法比较各组凋亡细胞,免疫组化方法比较各组高迁移率族蛋白B1(HMGB1)、核因子-κB(NF-κB)表达.结果 ①B组凋亡神经元明显多于正常对照组(H/R后3～24 h),C组凋亡细胞数目显著少于B组,三组比较差异有统计学意义.②B组HMGB1、NF-κB的表达较正常对照组明显增加,C组HMGB1、NF-κB表达较B组明显减少.结论 雌激素可使H/R后神经元HMGB1、NF-κB表达降低,抑制神经元凋亡,提高其存活率,这可能是其脑保护作用的机制之一. Abstract： Objective To explore the protective effects of estrogen on injured neurons induced by H/R and the mechanisms of that. Methods The cortical neurons cultured for 7 days were randomly divided into group A (normal control group), group B (H/R alone), group C (pretreatment with Estrogen -17βE2 and H/R). Then the apoptotic neurons were count by TUNEL, and the expression of HMGB1,NF- κB was observed by immunocytochemical technique, on each time point after reoxygenation 0,1,3,6,12,24 h of each group. Results ①The number of apoptotic neurons in group B was more than that in control group after H/R 3-24 h, and was less in group C than in group B. ②Compared with group A, the expression of HMGB1 and NF-κB was higher in group B,and was lower in group C than in group B. Conclusions Estrogen could decrease the expression of HMGB1 and NF-κB to inhibit neuronal apoptosis after H/R, which may be one of the mechanisms in which estrogen exerts its neuro-protective effect.     

Effects and mechanism of glucagon-like peptide-1 on injury of rats cardiomyocytes induced by hypoxia-reoxygenation

Background Although the insulinotropic role of glucagon-like peptide-1 （GLP-1） in type 2 diabetes mellitus has been substantiated, its role in cardioprotection remains largely unknown. This study aimed to determine the effects of GLP-1 on injury of rats cardiac myocytes induced by hypoxia-reoxygenation （H/R） and the possible mechanisms.
Methods The cultured neonatal rats cardiac myocytes were randomly divided into seven groups： the normal control group, the H/R group, the GLP-1＋H/R group, the GLP-1＋H/R＋UO126 （the p42/44 mitogen-activated protein kinase （MAPK） inhibitor） group, the GLP-1＋H/R＋LY294002 （phosphatidylinositol 3-kinase （PI3K） inhibitor） group, the H/R＋UO126 group, and the H/R＋LY294002 group. The lactate dehydrogenase （LDH） activity, apoptosis rate of cardiac myocytes, and caspase-3 activity were detected after the injury of H/R.
Results Compared with the normal control group, the activity of LDH, cardiac myocyte apoptosis rate, and caspase-3 activity all increased significantly in the H/R group （P 〈0.01）. Compared with the H/R group, these three indices all decreased in the H/R＋GLP-1 group （P 〈0.01）. However, the changes of LDH activity, apoptosis rate, and caspase-3 activity were inhibited by LY294002 and UO126 respectively.
Conclusions GLP-1 can directly act on cardiac myocytes and protect them from H/R injury mainly by inhibiting their apoptosis. Its mechanism may be through the PI3K-Akt pathway and the MAPK signaling pathway.     

Activation of NF-κB and its regulation on IL-6 expression during LPS-induced liver injury

Objective： To explore the kinetics of the activation of nuclear factor-kappa B （NF-κB） and its regulation of interleukin-6 （IL-6） expression during LPS induced liver injury. Methods： Kunming mice were randomly divided into 4 groups in order to observe the does effect relationship at 3h： normal saline solution （control） group, low （1 mg/kg）, middle （5 mg/kg）, and high （10 mg/kg） LPS-induced groups; 6 groups in order to observe the time-effect relationship of 5 mg/kg LPS injection： normal saline solution （control） group, 0.5, 1, 3, 5 and 8 h groups ; pyrrolidine dithiocarbamate （PDTC） intervened groups （3 h）： normal saline solution （control） group, 5 mg/kg LPS, 200 mg/kg PDTC, and 200 mg/kg PDTC＋5 mg/kg LPS groups. NF-κB activities of Kupffer cells were determined with electrophoretic mobility shift assay （EMSA） and expression levels of IL-6 were measured with enzyme-linked immunosorbent assay （ELISA）. Results： Does-effect of NF-κB activities in Kupffer cells after LPS injection 3 h： NF-κB activation could be detected in 1 mg/kg LPS group, reached the highest level in 5 mg/kg LPS group, and persisted in 10 mg/kg LPS group; time-course after 5 mg/kg LPS injection： the DNA-binding activity was observable at 0.5 h after LPS injection, increased significantly at 3 h, and persisted for at least 8 h; in addition, antioxidant PDTC could inhibit the activation of NF-κB significantly. The kinetics of IL-6 level in liver tissues during LPS-induced liver injury were that IL-6 level after 3 h of injection increased first and then reduced; the same trend was observed in the time-course on IL-6 level after LPS injection; PDTC could significantly inhibit the release of IL-6. Correlation analyses revealed that IL-6 level was significantly and positively correlated with the activation of NF-κB. Conclusion ： NF-κB in Kupffer cells can be activitied during LPS-induced liver injury to some extent, and NF-κB may have some regulation on the expression of IL-6.     

Relationship between Carbachol Hyperstimulation-induced Pancreatic Intracelluar Trypsinogen and NF-κB Activation in Rats in vitro

The relationship between intracelluar trypsinogen activation and NF-κB activation in rat pancreatic acinar cells induced by M3 cholinergic receptor agonist （carbachol） hyperstimulation was studied. Rat pancreatic acinar cells were isolated, cultured and treated with carbachol, the active protease inhibitor （pefabloc） and NF-κB inhibitor （PDTC） in vitro. Intracelluar trypsin activity was measured by using a fluorogenic substrate. The activity of NF-κB was monitored by using electrophoretic mobility shift assay. The results showed that after pretreatment with 2 mmol/L pefabloc, the activities of trypsin and NF-κB in pancreatic acinar cells treated with high concertrations of carbachol （10^-3 mol/L） in vitro was significantly decreased as compared with control group （P〈0.01 ）. The addition of 10^-2 mol/L PDTC resulted in a significant decrease of NF-κB activities in pancreatic acinar cells after treated with high concertrations of carbachol （10^-3 mol/L） in vitro, but the intracelluar trypsinogen activity was not obviously inhibited （P〉0.05）. It was concluded that intracelluar trypsinogen activation is likely involved in the regulation of high concertrations of carbachol-induced NF-κB activation in pancreatic acinar cells in vitro. NF-κB activation is likely not necessary for high concertrations of carbachol-induced trypsinogen activation in pancreatic acinar cells in vitro.     

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.     

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

Objective To investigate the effect ofperoxisome proliferator-activated receptor-α (PPARα) and PPARγ activators on tumor necrosis factor-α (TNFα) expression in neonatal rat cardiac myocytes.Methods Primary cultures of cardiac myocytes from 1- to 3-day-old Wistar rats were prepared, and myocytes were exposed 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 PPARγexpression in cultured cardiac myocytes. Transient transfection of TNFα promoter with or without nuclear factor-kappaB (NF-κB) binding site to cardiac myocytes was performed.Results 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 PPARγ mRNA expression when cardiac myocytes were pretreated with fenofibrate or pioglitazone. Proportional suppression of TNFαpromoter 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-κB binding site (-182/ 17).Conclusions PPARα and PPARγ activators may inhibit cardiac TNFα expression but not accompanied by change of PPARα or PPARγmRNA 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-κB pathway.     

Protective effects of hydroxyethyl starch 130/0.4 against myocardial ischemia/reperfusion injury in rats

Background  The effects of hydroxyethyl starch 130/0.4 (HES130/0.4) on myocardial ischemia/reperfusion (I/R) injury and its mechanism are uncertain. The aim of this study was to investigate the protective effects of HES 130/0.4 on myocardial I/R injury.

Methods  Forty-eight Sprague-Dawley rats were assigned to sham-operation group (S group), ischemia-reperfusion group (I/R group), albumin-I/R group (A-I/R group) and HES130/0.4-I/R group (H-I/R group). The fluids were administered at 25 minutes after ischemia. H-I/R group was given 7.5 ml/kg of HES 130/0.4; I/R group and A-I/R group received the same volume of normal saline and 5% albumin, respectively. The rats in S group were sham operated and received the same fluid as I/R group. After 30 minutes of ischemia and 3 hours of reperfusion, blood samples were taken for cytokines assay, myocardium was excised for detection of NF-κB activity and myocardial infarction areas were taken for immunohistochemical analysis.

Results  Hemodynamic parameters of H-I/R group were better than I/R and A-I/R groups at all designated time points. The results of 2,3,5-triphenyl-tetrazolium (TTC) and HE staining were better in the H-I/R group. Myeloperoxidase (MPO), NF-κB activity and concentrations of TNF-α, IL-1β were elevated markedly in I/R groups. HES130/0.4 lessened the release of TNF-α and IL-1β consistent with the reduction of MPO activity, and HES 130/0.4 inhibited the activity of NF-κB in H-I/R group. The number of apoptotic cells in the H-I/R group was also significantly reduced compared with I/R and A-I/R group

Conclusion  HES130/0.4 has a protective effect on I/R injured myocardium, probably by inhibiting NF-κB activity, reducing the release of pro-inflammatory cytokines and interfering with the apoptosis of cardiomyocytes.

     

Expression of NF-κB in hRPE Cells Stimulated by PDTC and IL-1β

The constitutive expression of nuclear-factor-κB (NF-κB) in human pigment epithelial (hRPE) cells cultivated in vitro and the possible changes when incubated with PDTC and IL-I were investigated. The synchronized hRPE cells in vitro were divided into two groups. In nonPDTC group, hRPE cells were exposed respectively to IL-1β and NS (for detecting the constitutive expressions of NF-κB in hRPE cells) ; In PDTC group, PDTC-pretreated hRPE cells were exposed respectively to IL-1β?Aand NS. (for detecting the constitutive expression of NF-κB in PDTC-pretreated hRPE cells). The expression of NF-κB in hRPE cells in two groups was detected by immunofluorescence stain and flow cytometry. The results showed that the constitutive expression of NF-κB in hRPE cells in vitro was 8.05 %, and increased to 30.26 % by IL-1β. After PDTC pretreatment, the constitutive expression of NF-κB in hRPE cells was decreased to 3.74%, and 3.66 % by IL-l,respectively. It was concluded that the expressions of NF-κB in hRPE cells could be increased significantly by IL-1βand depressed effectively by PDTC. Also, PDTC could significantly inhibit the activation of NF-κB induced by IL-1β.     

Effects of Ethyl Pyruvate on Myocardial Apoptosis and Expression of Bcl-2 and Bax Proteins after Ischemia-reperfusion in Rats

In order to study the effects of ethyl pyruvate on cardiomyocyte apoptosis following ischemia/reperfusion （I/R） in vitro and the expression of Bcl-2 and Bax proteins, isolated rat hearts were perfused in a Langendorff model. Twenty-four rats were randomly divided into 3 groups （n=8 in each group）： control group was perfused for 120 min. In the I/R group, after 30 min stabilization the injury was induced by 30 min global ischemia followed by 60 min reperfusion. Ethyl pyruvate （EP） group was set up with the same protocol as I/R group except that it was supplied with 2 mmol/L EP 15 rain before ischemia and throughout reperfusion. Myocardial malonaldehyde （MDA） content was measured. Myocardial apoptotic index （AI） was tested by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling （TUNEL） method. The expression of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax in cardiac myocytes was detected by immunohistochemistry. As compared with control group, the content of MDA, myocardial AI and the expression of Bcl-2, Bax proteins were increased significantly in I/R group, but the content of MDA, myocardial AI and the expression of Bax protein were decreased obviously and the expression of Bcl-2 protein was up-regulated in EP group （P〈0.05）. These results demonstrate that EP could inhibit apoptosis of cardiac myocytes possibly via alleviating oxidative stress, up-regulating Bcl-2 and down-regulating Bax proteins.     

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.     

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.     

Comparison of the effects of autotransfusion and homologous transfusion on milieu interieur and secretion of erythropoietin

Objective To compare the effects of autotransfusion and homologous transfusion on milieu interieur and secretion of erythropoietin (EPO). Methods Thirty patients aged 8-21 yr, undergoing surgical correction of kyphoscoliosis were randomly divided into two groups of fifteen:group A and group B. In group A patients received homologous transfusion during operation, while in group B shed blood was collected from operative field and after filtration RBCs were separated by a differential centrifugation and washed in normal saline and reinfused. Anesthesia was induced with fentanyl 2 μg· kg-1 ,propofol 1 mg·kg-1 and vecuronium 0.1 mg·kg-1 and maintained with inhalation of isoflurane and 50 % N2O in oxygen and intermittent iv boluses of vecuronium and fentanyl. Blood routine, blood gases, electrolytes, plasma osmotic pressure and activated clotting time (ACT) were measured before operation, 2 h after skin incision and at the end of surgery. Blood EPO concentration was measured before operation,at the end of     

Increased expression and activity of MMP-9 in C-reactive protein- induced human THP-1 mononuclear cells is related to activation of nuclear factor kappa-B

The relation between the expression and activity of MMP-9 in C-reactive protein （CRP）-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B （NF-κB） was studied to investigate the possible role of CRP in plaque destabilization. Human THP-1 cells were incubated in the presence of CRP at 0 （control group）, 25, 50 and 100 μg/mL （CRP groups） for 24 h. In PDTC （a specific NF-κB inhibitor） group, the cells were pre-treated with PDTC at 10 μmol/L and then with 100 μg/mL CRP. The conditioned media （CM） and human THP-1 cells in different groups were harvested. MMP-9 expression in CM and human THP-1 cells was measured by ELISA and Western blotting. MMP-9 activity was assessed by fluorogenic substrates. The expression of NF-κB inhibitor α （IκB-α） and NF-κB p65 was detected by Western blotting and ELISA respectively. The results showed that CRP increased the expression and activity of MMP-9 in a dose-dependent manner in the human THP-1 cells. Western blotting revealed that IiB-α expression was decreased in the cells with the concentrations of CRP and ELISA demonstrated that NF-κB p65 expression in the CRP-induced cells was increased. After pre-treatment of the cells with PDTC at 10 μmol/L, the decrease in IκB-α expression and the increase in NF-κB p65 expression in the CRP-induced cells were inhibited, and the expression and activity of MMP-9 were lowered too. It is concluded that increased expression and activity of MMP-9 in CRP-induced human THP-1 cells may be associated with activation of NF-κB. Down-regulation of the expression and activity of MMP-9 may be a new treatment alternative for plaque stabilization by inhibiting the NF-κB activation.     

Pro-apoptotic role of NF-κB pathway inhibition in lipopolysaccharide stimulated polymorphonuclear neutrophils

Objective To investigate the role of nuclear factor kappa B (NF-κB) pathway inhibition in lipopolysaccharide (LPS)-stimulated apoptosis of polymorphonuclear neutrophils (PMNs).Methods Rats with acute lung injury induced by LPS intratracheal instillation and cultured human venous PMNs were studied. Pyrrolidine dithiocarbamate (PDTC) and gliotoxin were used as NF-κB inhibitors. Additionally, to explore the role of extracellularly regulated protein kinase as an upstream signal in NF-κB pathway on regulating LPS-stimulated PMN apoptosis, PD098059, the specific inhibitor of extracellularly regulated protein kinase, was also applied. The lung injury was determined by protein content and PMN numbers in bronchoalveolar lavage fluid. PMN apoptosis was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) end labeling and DNA fragmentation. IκBα degradation was analyzed by Western blot. NF-κB DNA binding activity was detected by an electrophoretic mobility shift assay.Results (1) The increase of protein content and PMN numbers in bronchoalveolar lavage fluid induced by LPS (100μg per rat) intratracheal instillation were alleviated by PDTC (50, 100, or 200mg/kg, i. p. ) in a dose-dependent manner. (2) PMNs apoptosis in vivo or in vitro was delayed by LPS, and accelerated by PDTC, gliotoxin or PD098059 pretreatment. (3) IκBα degradation and increased NF-KB DNA binding activity mediated by LPS were inhibited by PDTC, gliotoxin or PD098059 pretreatment.Conclusion Inhibition of either NF-κB itself or the upstream signals in NF-κB pathway such as extracellularly regulated protein kinases has therapeutic effect on LPS-induced acute lung injury, in which the dysregulation of PMN apoptosis plays an important role.     

The protective effect of puerarin against myocardial reperfusion injury. Study on cardiac function.

In order to find out if puerarin could protect the hearts from myocardial reperfusion injury after cardiac arrest, twelve dogs divided into two equal groups were placed on moderately hypothermic cardiopulmonary bypass and their hearts were subjected to 140 min of cold cardioplegic arrest and 60 min of reperfusion. In the control group, the hearts were perfused with a crystalloid cardioplegic solution (CPS) through the aortic root every 20 min during arrest. In the treated group, the hearts received CPS containing puerarin (2 mg/kg). Cardiac hemodynamic variables were monitored throughout the experiments. Left ventricular function curves were formed before ischemia and after 60 min of reperfusion. The results showed that the recovery of left ventricular function in the treated group was significantly better than that in the controls (81 +/- 11% versus 39 +/- 7%, P less than 0.01). Compared with preischemic values, the increase of coronary blood flow (CBF) at cardiac arrest in the puerarin-treated group was higher than that in the control group (214 +/- 11 versus 177 +/- 4 ml/min, P less than 0.01). The data indicate that puerarin has protective effects on the cardiac function after prolonged arrest and reperfusion.

     

Tonglian Decoction(通莲汤) Arrests the Cell Cycle in S-phase by Targeting the Nuclear Factor-Kappa B Signal Pathway in Esophageal Carcinoma Eca109 Cells

Objective:To investigate the anti-tumor activity and molecular mechanism of Tonglian Decoction(通莲汤,TLD) on esophageal carcinoma Eca109 cells.Methods:Eca109 cells were treated with TLD and its separated formulae,including the clearing-heat and detoxification formula(Q),activating-blood and promoting-qi formula(H) and nourishing-yin and blood formula(Z).Cell proliferation was measured using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay,cell morphology was observed using a microscope,the cell cycle was measured using flow cytometry and the activity of the nuclear factor-kappa B(NF-κB) signal pathway was detected by Western blot.Results:The half maximal inhibitory concentrations of TLD,Q and H were 386,771 and 729 mg/L,respectively.TLD,Q and H significantly inhibited cell proliferation,with 69.43%,60.84%and 61.90%of treated cells in the G1 phase of the cell cycle.The percentage of cells in S phase increased significantly after treatment with TLD,Q,and H compared with the control group(P0.05),and TLD showed the strongest effect.Z had no influence on the cell cycle compared with the control group(P0.05).Western blot detection indicated slight differences in the inhibition of the NF- k B pathway by the different formulae.TLD formula strongly inhibited IKKβ,NF-κB,interleukin-6 and tumor necrosis factor-α expression compared with the control group.Conclusions:TLD inhibited Eca109 cell proliferation by arresting cells in S phase.The possible mechanism might be related to inhibiting the NF- κB transduction cascade.The combination of the herbs found in the three separate formulae,H,Q and Z,work synergistically in TLD to produce the inhibitory effects of TLD treatment on Eca109 proliferation.