腹腔内注射脂多糖对大鼠黑质多巴胺能神经元和小胶质细胞形态学影响及炎性因子变化

目的观察腹腔注射脂多糖(lipopolysaccharide,LPS)后,大鼠黑质多巴胺能神经元和小胶质细胞形态学变化及炎性因子的变化。方法健康2月龄、12月龄斯普雷格-道利(Sprague-Dawley,SD)大鼠经腹腔注射LPS(1 mg/kg)后,分别于6 h,12 h,24 h,48 h,1周处死,用链霉菌抗生物素蛋白-过氧化物酶连结(streptavidin-peroxidase,SP)法进行抗酪氨酸羟化酶(tyrosine hydroxylase,TH)和抗钙离子结合蛋白1(ionized calcium binding adapter molecule 1,Iba-1)免疫组织化学染色,观察不同时间点脑黑质多巴胺能神经元阳性存活率及黑质小胶质细胞的激活情况。酶联免疫吸附测定(enzyme-linked immunosorbent assay,ELISA)法分别检测相应时间点血及脑脊液中肿瘤坏死因子α(tumor necrosis factorα,TNF-α)、白细胞介素6(interleukin 6,IL-6)及白细胞介素1β(interleukin 1β,IL-1β)的变化。结果腹腔注射LPS(1 mg/kg)后,老龄组大鼠小胶质细胞呈明显激活改变,且早于青年组小胶质细胞的高峰;各组小胶质细胞的激活早于多巴胺能神经元的损毁;老年组脑脊液中各种炎性因子水平高于青年组。结论老化因素与外周炎性介质诱发的中枢神经系统(central nervous system,CNS)炎性反应有关。

腮腺炎合并脑膜脑炎急性期脑脊液中IL-1、IL-6、IL-8、TNF-α的变化及其意义

为探讨细胞因子在病毒性脑炎发病中的作用及意义,对30例腮腺炎合并脑膜脑炎患儿脑脊液测定了IL-1、IL-6、IL-8(白细胞介素-1、6、8),TNF-α(肿瘤坏死因子),结果发现急性期腮脑患儿脑脊液中上述细胞因子均较对照组明显增高(P<0.01),说明腮腺炎合并脑膜脑炎的发病与IL-1、IL-6、IL-8、TNF-α密切相关。

Sustained Contraction of Isolated Rabbit Thoracic Aortic Rings in Endothelial-dependent Manner Induced by βγ-CAT

In vertebrates, non-lens βγ-crystallins are widely expressed in various tissues and their functions are not well known. The molecular mechanisms of trefoil factors （TFFs）, which involved in mucosal healing and tumorigenesis, have remained elusive. βγ-CAT is a novel multifunctional protein complex of non-lens βγ-crystallin and trefoil factor from frog skin secretions. Here we report that βγ-CAT could induce sustained contraction of isolated rabbit aortic rings in dosage （2-35nmol/L） and endothelium dependent manners （P〈0.01 ）. In addition, in situ immunofluorescence indicated that positive TNF-α signals were mainly detected at the endothelial cell layer of βγ-CAT （25nmol/L） treated rings. Furthermore, βγ-CAT induced primary cultured rabbit thoracic aortic endothelial cells （RAECs） rapidly to release TNF-α. After βγ-CAT （25nmol/L） treated for 10 and 30min, the levels of the endothelial cells released TNF-ct were 34.17±5.10 pg/mL and 98.01±4.67 pg/mL （P〈0.01）, respectively. In conclusion, βγ-CAT could induce sustained contraction of isolated aortic rings, and the contractile effect might be partially explained by the release of TNF-α. These findings will give new insight into understanding the functions and physiological roles of non-lens βγ-crystallins and trefoil factors.

Arsenic trioxide inhibites transgenic tumor necrosis factor-α promoter activity in vascular smooth muscle cells and THP-1 monocytes in vitro

Aim This study was to evaluate the effect of arsenic trioxide （As2O3） on the transgenic TNF-α promoter activity in cultured vascular smooth muscle cells （VSMCs） and THP-1 monocytes. Methods Human TNF-α promoter was constructed by reporter gene system and was transiently transfected into VSMCs and THP-1 in vitro. The promoter activity was tested by luciferase activity with or without LPS and Ang Ⅱ stimulation, before and after different dosage of As2O3 treatment. Results 1. TNF-α promoter effectively expressed in VSMCs and THP-1 compared with CMV promoter （58.3% and 80.9%, respectively）. Both LPS and Ang Ⅱ significantly up-regulated TNF-α promoter activity （P〈0.05）. 2. As2O3 significantly inhibited, both intact and LPS/Ang Ⅱ stimulated promoter activity, in a dose dependent manner （P〈0.05）, and in both cell type. Conclusion These results manifested that, the inhibition effect of As2O3 on the activity of human TNF-α promoter indicated its potential inhibition on pro-inflammatory cytokine genes expression at transcriptional level and its potential anti-inflammatory property in the cardiovascular system.

Changes of Src-suppressed C kinase substrate expression in cytokine induced reactive C6 glioma cells

Objective To investigate effect of tumor necrosis factor-or （TNF-α） on the Src-suppressed C kinase substrate （SSeCKS） in C6 glioma cells. Methods Cultured C6 glioma cells were randomly divided into two groups. In time-dependent group, cells were cultured with TNF-α （2 ng/mL） for 0 h, 1 h, 3 h, 6 h, 12 or 24 h, respectively; in dose-dependent group, cells were cultured with TNF-α （0 ng/mL, 0.02 ng/mL, 0.2 ng/mL, or 2 ng/mL） for 6 h. The expression of SSeCKS was detected by Realtime PCR and Western blot analysis, and immunocytochemistry was used to investigate SSeCKS＇s subcellular localization. Results TNF-α induced rapid phosphorylations of protein kinase C （PKC） substrates in C6 glioma cells, and upregulated SSeCKS expression in a time and concentration dependent manner. Immunocytochemistry suggested that SSeCKS was localized in the cyroplasm and the leading end of podosomal extensions in control groups, while TNF-α induced translocation of SSeCKS perinuclear. This effect could be partly reversed by PKC inhibitor Ro-31-8220. Conclusion TNF-α activates PKC and upregulates SSeCKS expression in C6 glioma cells. These effects are associated with PKC activity, suggesting that SSeCKS plays a role in response to glia activation in PKC mediated pathway.

Lipopolysaccharide preconditioning induces protection against lipopolysac-charide -induced neurotoxicity in organotypic midbrain slice culture

Objective To identify the protective effect of lipopolysaccharide （LPS） preconditioning against LPS-induced inflammatory damage in dopaminergic neurons of midbrain slice culture and the possible mechanisms. Methods After cultured in vitro for 14 d, the rat organotypic midbrain slices were pretreated with different concentrations （0, 1, 3, 6 or 10 ng/mL） of LPS for 24 h followed by treatment with 100 ng/mL LPS for 72 h. The whole slice viability was detelmined by measurement of the activity of lactic acid dehydrogenase （LDH）. Tyrosine hydroxylase-immunoreactive （TH-IR） neurons and CD 1 1 b/c equivalent-immunoreactive （OX-42-IR） microglia in the slices were observed by immunohistochemical method, and tumor necrosis factor-α （TNF-α levels in the culture media were detected by enzymelinked immunosorbent assays （ELISA）. Results In the slices treated with 100 ng/mL LPS for 72 h, the number of TH-IR neurons reduced from 191± 12 in the control slices to 46±4, and the LDH activity elevated obviously （P 〈 0.01）, along with remarkably increased number of OX-42-IR cells and production of TNF-α （P 〈 0.01）. Preconditioning with 3 or 6 ng/mL LPS attenuated neuron loss （the number of TH-IR neurons increased to 126± 12 and 180± 13, respectively） and markedly reduced LDH levels （P 〈 0.05）, accompanied by significant decreases of OX-42-IR microglia activation and TNF-α production （P 〈 0.05）. Conclusion Low-dose LPS preconditioning could protect dopaminergic neurons against inflammatory damage in rat midbrain slice culture, and inhibition of microglial activation and reduction of the proinflammatory factor TNF-α production may contribute to this protective effect. Further understanding the underlying mechanism of LPS preconditioning may open a new window for treatment of Parkinson＇s disease.

Effects of β-Aescin on the expression of nuclear factor-κB and tumor necrosis factor-α after traumatic brain injury in rats

To investigate the inhibiting effect of β-Aescin on nuclear factor-κB (NF-κB) activation and the expression of tumor necrosis factor-α (TNF-α) protein after traumatic brain injury (TBI) in the rat brain, 62 SD rats were subjected to lateral cortical impact injury caused by a free-falling object and divided randomly into four groups: (1) sham operated (Group A); (2) injured (Group B); (3) β-Aescin treatment (Group C); (4) pyrrolidine dithocarbamate (PDTC) treatment (Group D). β-Aescin was administered in Group C and PDTC treated in Group D immediately after injury. A series of brain samples were obtained directly 6h, 24 h and 3 d respectively after trauma in four groups. NF-κB activation was examined by Electrophoretic Mobility Shift Assay (EMSA); the levels of TNF-α protein were measured by radio-immunoassay (RIA); the water content of rat brain was measured and pathomorphological observation was carried out. NF-κB activation, the levels of TNF-α protein and the water content of rat brain were significantly increased (P＜0.01) following TBI in rats. Compared with Group B, NF-κB activation (P＜0.01), the levels of TNF-α protein (P＜0.01) and the water content of brain (P＜0.05) began to decrease obviously after injury in Groups C and D.β-Aescin could dramatically inhibit NF-κB activation and the expression of TNF-α protein in the rat brain, alleviate rat brain edema, and that could partially be the molecular mechanism by which β-Aescin attenuates traumatic brain edema.

Association of polymorphism of tumor necrosis factor-alpha gene promoter region with outcome of hepatitis B virus infection

AIM： To determine whether -238G/A and -857C/T polymorphisms of tumor necrosis factor-alpha （TNF-α）, gene promoter and hepatitis B （HB） viral genotypes were associated with outcomes of HBV infection. METHODS： A total of 244 HBV self-limited infected subjects, 208 asymptomatic carriers, and 443 chronic HB patients were recruited to conduct a case-control study. TNF-α -238G/A and -857C/T gene promoter polymorphisms were examined by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP）, and HBV genotypes were examined by nested PCR. RESULTS： The positive rate of HBV DNA in asymptomatic carder group and chronic HB group was 46.6% and 49.9%, respectively. HBV genotype proportion among the asymptomatic carriers was 2.1% for genotype A, 25.8% for genotype B, 68.0% for genotype C, and 4.1% for genotype B＋C mixed infection, and 0.9% for genotype A, 21.7% for genotype B, 71.5% for genotype C, 5.9% for genotype B＋C mixed infection in chronic HB group. There was no significant difference in genotype distribution between the asymptomatic carrier group and chronic HB group （X^2 = 1.66, P = 0.647）. The frequency of -238GG genotype in self-limited group was 95.1%, significantly higher than 90.7% in chronic HB group and 89.0% in asymptomatic carrier group （P = 0.041 and P = 0.016, respectively）.The frequency of TNF-α-857 CC in chronic HB group was 79.7%, significantly higher than 64.4% in asymptomatic carrier group and 70.9% in self-limited group （P〈0.001 and P = 0.023, respectively）. A multiple logistic regression analysis revealed that TNF-α-238GA and -857CC were independently associated with chronic HB after gender and age were adjusted.CONCLUSION： TNF-α promoter variants are likely to play a substantial role in the outcome of HBV infection.

TUMOR NECROSIS FACTOR-ALPHA POLYMORPHISM AND SECRETION IN MYASTHENIA GRAVIS

Objective To analyze the relationship between tumor necrosis factor-alpha (TNFα) gene promoter -308 polymorphism and myasthenia gravis (MG) in Chinese and analyze secretion of TNFα in peripheral blood mononuclear cells (PBMC) in MG patients. Methods A biallelic polymorphism at position -308 in the promoter of TNFα gene was screened by PCR amplification and NcoI recognition site. One hundred and twenty-three MG cases and 115 healthy controls were included in this study. MG patients were classified to different groups according to clinical type, age at onset, and sex respectively. PBMC were isolated from 20 patients and 20 healthy controls, and then cultured in the presence or absence of phytohemag- glutinin (PHA) and acetycholine receptors (AchR). The supernatants were harvested after incubation and stored until TNFα was assayed by enzyme-linked immunosorbent assay. Results The frequency of TNFα-308 allele 2 (A) was found significantly increase in MG patients and showed a trend especially in late onset (≥ 40 years) and male patients (P < 0.05). The allele A had no relationship with thymic pathogenesis in MG patients. But frequency of allele A was significantly higher in general type than in ocular type (P < 0.05). MG patients had a higher inducible level of TNFα by PHA and AchR, and could be down regulated after treatment. Conclusion Polymorphism in TNFα gene promoter -308 is associated with onset of MG. The microsatellite allele TNFα2 confer risk for the development of MG in Chinese patients. MG patients have a higher inducible level of TNFα.

Tumor necrosis factor-alpha induces apoptosis of enterocytes in mice with fulminant hepatic failure

AIM: To explore the alterations of intestinal mucosa morphology, and the effects of tumor necrosis factor a (TNFα) on enterocyte apoptosis in mice with fulminant hepatic failure (FHF). METHODS: Liver damage was induced by lipopolysaccharide (LPS)/TNF-α in D-galactosamine (GaIN) sensitized BALB/c mice. There were 40 mice in normal saline (NS)-treated group, 40 mice in LPS-treated group, 40 mice in GaIN-treated group, 120 mice in GaIN/ LPS-treated group and 120 mice in GaIN/ TNFα-treated group. Each group was divided into five subgroups of eight mice each. Serum samples and liver, intestinal tissues were respectively obtained at 2, 6,9,12 and 24 h after administration. Anti-TNFa monoclonal antibody was injected intravenously into GaIN/LPS-treated mice. Serum TNFα levels were determined by enzyme linked immunosorbent assays (ELISA). Serum ALT levels were determined using an automatic analyzer. The intestinal tissues were studied under light microscope and electron microscope at 2, 6, 9,12 and 24 h in mice with fulminant hepatic failure, respectively. Enterocyte apoptosis was determined by terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) method. The expression of tumor necrosis factor receptor 1 (TNFR1) in intestinal tissue was tested by immunohistochemistry Envision Two Steps. RESULTS: Gut mucosa was morphologically normal at all time points in all groups, but typical apoptotic cells could be seen in all experimental groups under electron microscope. Apoptosis rate of gut mucosal epithelial cells were significantly increased at 6, 9 and 12 h, peaked at 12 h in mice with fulminant hepatic failure. TNFa induced apoptosis of enterocytes in mice with FHF. The integrated OD (IOD) levels of TNFa receptor 1 protein expressed in the intestine of mice with GaIN/LPS and GaIN/ TNFα induced FHF at 2, 6, 9, 12 and 24 h after GaIN/LPS and GaIN/TNFα administration were 169.54±52.62/905.79±111.84,11 350.67±2 133.26/28 160.37±4 601.67, 25 781.00±2 277.75/122 352.30±49 412.40, 5 241.53±3 007.24/ 49 157.93±9 804.88, 7 086.13±1 031.15/3 283.45±127.67, respectively, compared with those in control groups (with NS, LPS and GaIN administration, respectively). IOD level of TNFR1 changed significantly at 6, 9 and 12 h after GaIN/LPS and GalN/TNFa administration. The expression of TNFR1 protein was significantly higher at 9 h after GaIN/LPS and GaIN/TNFα administration than that in control groups. Protein expression of TNFR1 was positively correlated with enterocyte apoptosis. CONCLUSION: TNFα can induce apoptosis of enterocytes in mice with FHF. Anti-TNFα IgG can inhibit this role.

BCL-XL regulates TNF-α-mediated cell death independently of NF-κB, FLIP and IAPs

Upon activation, tumor necrosis factor alpha （TNF-α） receptor can engage apoptotic or survival pathways. Inhibition of macromolecular synthesis is known to sensitize cells to TNF-α-induced cell death. It is believed that this sensitization is due to the transcriptional blockade of genes regulated by NF-κB. Nevertheless, such evidence has remained elusive in the nervous system. Here, we show that TNF-α cannot normally induce apoptosis in PC12 cells or cortical neurons. However, cells treated with Actinomycin D （ActD） become susceptible to TNF-α-induced cell death through the activation of caspase-8, generation of tBid and activation of caspase-9 and -3. Analysis of several proteins involved in TNF-α receptor signaling showed no significant downregulation of NF-κB target genes, such as IAPs or FLIP, under such conditions. However, Bcl-XL protein levels, but not those of Bcl-2, Bax and Bak, are reduced by ActD or TNF-α/ ActD treatments. Moreover, Bcl-xL overexpression fully protects cells against TNF-α/ActD-induced cell death. When endogenous levels of Bcl-XL are specifically downregulated by lentiviral-based RNAi, cells no longer require ActD to be sensitive to TNF-α-triggered apoptosis. Furthermore, Bcl-xL downregulation does not affect TNF-α-mediated NF-κB activation. Altogether, our results demonstrate that Bcl-XL, and not Bci-2, FLIP or IAPs, acts as the endogenous regulator of neuronal resistance/sensitivity to TNF-α-induced apoptosis in an NF-κB-independent manner.

Omega-3 polyunsaturated fatty acids promote liver regeneration after 90% hepatectomy in rats

AIM:To evaluate the effectiveness of omega-3 polyunsaturated fatty acid(ω-3 PUFA) administration on liver regeneration after 90% partial hepatectomy(PH) in rats.METHODS:ω-3 PUFAs were intravenously injected in the ω-3 PUFA group before PH surgery.PH,sparing only the caudate lobe,was performed in both the control and the ω-3 PUFA group.Survival rates,liver weight/body weight ratios,liver weights,HE staining,transmission electron microscope imaging,nuclearassociated antigen Ki-67,enzyme-linked immunosorbent assay and signal transduction were evaluated to analyze liver regeneration.RESULTS:All rats in the control group died within 30 h after hepatectomy.Survival rates in the ω-3 PUFA group were 20/20 at 30 h and 4/20 1 wk after PH.Liver weight/body weight ratios and liver weights increased significantly in the ω-3 PUFA group.The structure of sinusoidal endothelial cells and space of Disse was greatly restored in the ω-3 PUFA group compared to the control group after PH.In the ω-3 PUFA group,interleukin(IL)-4 and IL-10 levels were significantly increased whereas IL-6 and tumor necrosis factor-levels were dramatically decreased.In addition,activation of protein kinase B(Akt) and of signal transducer and activator of transcription 3 signaling pathway were identified at an earlier time after PH in the ω-3 PUFA group.CONCLUSION:Omega-3 polyunsaturated fatty acids may prevent acute liver failure and promote liver regeneration after 90% hepatectomy in rats.

Moxibustion inhibits interleukin-12 and tumor necrosis factor alpha and modulates intestinal flora in rat with ulcerative colitis

AIM: To investigate the effect of moxibustion on intestinal flora and release of interleukin-12 (IL-12) and tumor necrosis factor-α (TNF-α) from the colon in rat with ulcerative colitis (UC). METHODS: A rat model of UC was established by local stimulation of the intestine with supernatant from colonic contents harvested from human UC patients. A total of 40 male Sprague-Dawley rats were randomly divided into the following groups: normal (sham), model (UC), herb-partition moxibustion (HPM-treated), and positive control sulfasalazine (SA-treated). Rats treated with HPM received HPM at acupuncture points ST25 and RN6, once a day for 15 min, for a total of 8 d. Rats in the SA group were perfused with SA twice a day for 8 d. The colonic histopathology was observed by hematoxylin-eosin. The levels of intestinal flora, including Bifidobacterium, Lactobacillus, Escherichia coli (E. coli), and Bacteroides fragilis (B. fragilis), were tested by real-time quantitative polymerase chain reaction to detect bacterial 16S rRNA/DNA in order to determine DNA copy numbers of each specific species. Immunohistochemical assays were used to observe the expression of TNF-α and IL-12 in the rat colons. RESULTS: HPM treatment inhibited immunopathology in colonic tissues of UC rats; the general morphological score and the immunopathological score were significantly decreased in the HPM and SA groups compared with the model group [3.5 (2.0-4.0), 3.0 (1.5-3.5) vs 6.0 (5.5-7.0), P < 0.05 for the general morphological score, and 3.00 (2.00-3.50), 3.00 (2.50-3.50) vs 5.00 (4.50-5.50), P < 0.01 for the immunopathological score]. As measured by DNA copy number, we found that Bifidobacterium and Lactobacillus, which are associated with a healthy colon, were significantly higher in the HPM and SA groups than in the model group (1.395 ± 1.339, 1.461 ± 1.152 vs 0.045 ± 0.036, P < 0.01 for Bifidobacterium, and 0.395 ± 0.325, 0.851 ± 0.651 vs 0.0015 ± 0.0014, P < 0.01 for Lactobacillus). On the other hand, E. coli and B. fragilis, which are associated with an inflamed colon, were significantly lower in the HPM and SA groups than in the model group (0.244 ± 0.107, 0.628 ± 0.257 vs 1.691 ± 0.683, P < 0.01 for E. coli, and 0.351 ± 0.181, 0.416 ± 0.329 vs 1.285 ± 1.039, P < 0.01 for B. fragilis). The expression of TNF-α and IL-12 was decreased after HPM and SA treatment as compared to UC model alone (4970.81 ± 959.78, 6635.45 ± 1135.16 vs 12333.81 ± 680.79, P < 0.01 for TNF-α, and 5528.75 ± 1245.72, 7477.38 ± 1259.16 vs 12550.29 ± 1973.30, P < 0.01 for IL-12). CONCLUSION: HPM treatment can regulate intestinal flora and inhibit the expression of TNF-α and IL-12 in the colon tissues of UC rats, indicating that HPM can improve colonic immune response.

Synergistic effect of bromocriptine and tumor necrosis factor-a on reversing hepatoceiiuiar carcinoma multidrug resistance in nude mouse MDRl model of liver neoplasm

AIM： To investigate the effect of bromocripUne （BCT） and tumor necrosis factor-α ClNF-α） on hepatocellular carcinoma （HCC） multidrug resistance （MDR） in nude mouse HDR model of liver neoplasm. METHODS： Human hepatocarcinoma cell line HepG2t drug resistant hepatocarcinoma cell line HepG2/adriamycin （ADM） and hepatocarcinoma cell line transfected with TNF-α gene HepG2JADM/TNF were injected into the liver of nude mice via orthotopic implantation and MDR model of liver neoplasm in vivo was established （HepG2t ADM, TNF, BCT groups）. Among these groups, BCT group and TNF group were treated with BCT through gastric canal. Each group was divided into control group and chemotherapy group. Size and weight of the tumor were measured. Furthermore, tumor his^logical character and growth of the nude mice were observed and their chemosensitivity was tested. MDR-associated genes and proteins （MRP, LRP） of implanted tumors were detected by immunohistochemistry, reverse transcriptase polymerase chain reaction, and apoptosis rate of hepatocarcinoma cells was detected by TUNEL assay. RESULTS： The nude mouse model of each cell line was inoculated successfully. The tumor growth rate and weight were significantly different among groups. After chemotherapy, abdominal cavity tumor growth inhibition rate was higher in BCT group （67%） compared to ADM and TNF groups, and similar to HepG2group （54%）. MDRI and LRPmRNA could be detected in all groups, but TNF-α was detected only in TNF and BCT groups. Furthermore, MDR1 and LRP protein expression of tumors in TNF and BCT groups was low similar to HepG2 group. The apoptosis rate of hepatocarcinoma cells was much higher in BCT group than in other groups with TUNEL assay. CONCLUSION： BCT and TNF-a can reverse HCC MDR in nude mouse MDR1 model of liver neoplasm. 2005 The WJG Press and Elsevier Inc. All rights reserved

Tumor necrosis factor-α-induced protein 1 and immunity to hepatitis B virus

AIM: To compare the gene expression profile in a pair of HBV-infected twins.METHODS: The gene expression profile was compared in a pair of HBV-infected twins.RESULTS: The twins displayed different disease outcomes. One acquired natural immunity against HBV,whereas the other became a chronic HBV carrier. Eightyeight and forty-six genes were found to be up- or downregulated in their PBMCs, respectively. Tumor necrosis factor-alpha-induced protein 1 (TNF-αIP1) that expressed at a higher level in the HBV-immune twins was identified and four pairs of siblings with HBV immunity by RTPCR. However, upon HBV core antigen stimulation,TNF-αIP1 was downregulated in PBMCs from subjects with immunity, whereas it was slightly upregulated in HBV carriers. Bioinformatics analysis revealed a K+channel tetramerization domain in TNF-αIP1 that shares a significant homology with some human, mouse, and C elegan proteins.CONCLUSION: TNF-αIP1 may play a role in the innate immunity against HBV.

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

Objective To investigate the effect of peroxisome proliferator-activated receptor-α(PPARα) and PPARγactivators 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 ex-posed to lipopolysaccharide (LPS) and varying concentrations of PPARαor PPARγactivator (fenofibrate or pioglitazone).RT-PCR and ELISA were used to measure TNFα, PPARα, and PPARγexpression in cultured cardiac myocytes. Transient tr-ansfection of TNFαpromoter 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 TNFαmRNA and protein expression in a dose-dependent manner. However, no significant changes were observed on PPARαor PPARγmRNA 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 TNFαpromoter (-721/+17) after being stimulated with LPS and fenofibrate or pioglitazone, whereas no change of promoter activity was observed with transfection of TNFαreporter construct in deletion of NF-κB binding site (-182/+17). Conclusions PPARαand PPARγactivators may inhibit cardiac TNFαexpression but not accompanied by change of PPARαor PPARγmRNA expression. Therefore PPARαand PPARγactivators appear to play a role in anti-inflammation. The mechanism may partly be involved in suppression of the NF-κB pathway.

Molecular cloning of Japanese eel Anguilla japonica TNF-α and characterization of its expression in response to LPS, poly I:C and Aeromonas hydrophila infection

As a potent pleiotropic cytokine, tumor necrosis factor-alpha （TNF-ct） plays an important role in innate immune responses. The cDNA sequence and genomic structure of the TNF-α gene （AjTNF-c0 in the Japanese eel （Anguilla japonica） were identified and characterized. The full-length AjTNF-α cDNA was 1 546 bp, including a 5＇-untranslated region （UTR） of 13 bp, a 3＇-UTR of 879 bp and an open reading frame of 654 bp encoding a protein of 218 amino acids. The full-length genomic sequence of AjTNF-ct was 2 392 bp and included four exons and three introns. The putative AjTNF-α protein contained TNF family signature motifs, including a protease cleavage site, a transmembrane domain and two conserved cysteine residues. Quantitative real-time reverse transcription PCR analysis revealed AjTNF-α expression in a wide range of tissues, with predominant expression in blood and liver. Lower levels of expression were seen in spleen, gills, kidney, intestine, heart, and skin, with very low levels in muscle. The modulation of AjTNF-ct expression after injection of eels with lipopolysaccharide （LPS）, the viral mimic, poly I：C, or Aeromonas hydrophila was assessed in blood, liver, and kidney. In blood, TNF-α mRNA levels increased rapidly and then rapidly decreased after stimulation with LPS, poly I：C or A. hydrophila. However, the response to LPS and A. hydrophila peaked at 6 h while for poly I：C the peak was at 12 h. In liver, after injection with A. hydrophila, an up- and down-regulation of AjTNF-ct expression occurred twice, peaking at 6 h and 24 h, respectively. No remarkable increase of AjTNF-α expression appeared in liver until 72 h after LPS or poly I：C treatment. In kidney, ApiNF-α expression increased significantly only at 72 h post-stimulation with LPS orA. hydrophila. Our results suggest that AjTNF-α plays an important role in fish in the defense against viral and bacterial infection.

Use of anti tumor necrosis factor-alpha monoclonal antibody for ulcerative jejunoileitis

Ulcerative jejunoileitis is an uncommon clinical syndrome consisting of abdominal pain,weight loss associated with diarrhea,and multiple inflammatory ulcerations and strictures of the small bowel.Ulcerative jejunoileitis can complicate established celiac disease or develop in patients de novo.Increased levels of tumor necrosis factor-alpha(TNF-α) in the small intestine of patients with untreated celiac disease are associated with a role in the immune pathogenesis of this disorder.No specific therapy has been shown to change the course of ulcerative jejunoileitis.We report a case of severe ulcerative jejunoileitis previously unresponsive to traditional therapies,including high dose corticosteroids and cyclosporine.The patient had a dramatic resolution of symptoms and a complete normalization of endoscopic findings after anti-TNF-α monoclonal antibody,infliximab(Remicade).

Expression of tumor necrosis factor-alpha converting enzyme in liver regeneration after partial hepatectomy

AIM:To study the expression of tumor necrosis factor- alpha converting enzyme (TACE) and evaluate its significance in liver regeneration after partial hepatectomy in vivo. METHODS: Male SD rats underwent 70% partial hepatec- tomy. The remaining liver and spleen tissue samples were collected at indicated time points after hepatectomy. TACE expression was investigated by Western blotting, immunohistochemistry, and serial section immunostaining. RESULTS: Expression of TACE in liver and spleen tissues after partial hepatectomy was a time-dependent alteration, reaching a maximal level between 24 and 48 h and remaining elevated for more than 168 h. TACE protein was localized to mononuclear cells (MNC), which infiltrated the liver from the spleen after hepatectomy. The kinetics of TACE expression was in accordance with the number of TACE-staining MNCs and synchronized with those of transforming growth factor-α (TGFα). In addition, TACE-staining MNC partially overlapped with CD3+ T lymphocytes. CONCLUSION: TACE may be involved in liver regenera- tion by pathway mediated with TGFα-EGFR in the cell- cycle progressive phase in vivo. TACE production and effect by paracrine may be a pathway of involvement in liver regeneration for the activated CD3+ T lymphocytes.

Defensive nature of Sargassum polycystum (Brown alga) against acetaminophen-induced toxic hepatitis in rats: Role of drug metabolizing microsomal enzyme system, tumor necrosis factor-a and fate of liver cell structural integrity

AIM： To assess the defensive nature of Sargassum polycystum （S. polycystum） （Brown alga） against acetaminophen （AAP）-induced changes in drug metabolizing microsomal enzyme system, tumor necrosis factor （TNF-α） and fine structural features of the liver during toxic hepatitis in rats. METHODS： Male albino Wistar strain rats used for the study were randomly categorized into 4 groups. Group Ⅰ consisted of normal control rats fed with standard diet. Group II rats were administered with acetaminophen （800 mg/kg body weight, intraperitoneally）. Group Ⅲ rats were pre-treated with S. polycystum extract alone. Group IV rats were orally pre-treated with S. polycystum extract （200 mg/kg body weight for 21 d） prior to acetaminophen induction （800 mg/kg body weight, intraperitoneally）. Serum separated and liver was excised and microsomal fraction was isolated for assaying cytochrome P450, NADPH Cyt P450 reductase and bs. Serum TNF-α was detected using ELISA. Fine structural features of liver were examined by transmission electron microscopy. RESULTS： Rats intoxicated with acetaminophen showed considerable impairment in the activities of drug metabolizing microsomal enzymes, such as cytochrome P450, NADPH Cyt P450 reductase and bs when compared with the control rats. The rats intoxicated with acetaminophen also significantly triggered serum TNF-a when compared with the control rats. These severe alterations in the drug metabolizing enzymes were appreciably pretreated with S. polycystum. prevented in the rats The rats pretreated withS. polycystum showed considerable inhibition in the elevation of TNF-α compared to the rats intoxicated with acetaminophen. The electron microscopic observation showed considerable loss of structural integrity of the endoplasmic reticulum, lipid infiltration and ballooning of mitochondria in the acetaminophen-intoxicated rats, whereas the rats treated with S. polycystum showed considerable protection against acetaminophen-induced alterations in structural integrity. CONCLUSION： These observations suggest that the animals treated with S. polycystum extract may have the ability to protect the drug metabolizing enzyme system and mitochondrial functional status from free radical attack, thereby showing its defense mechanism in protecting hepatic cells from acetaminophen toxic metabolite N-acetyl-para-benzoquinone-imine （NAPQI）.