Methamphetamine-induced neurotoxicity is attenuated in transgenic mice with a null mutation for interleukin-6

Increasing evidence implicates apoptosis as a major mechanism of cell death in methamphetamine (METH) neurotoxicity. The involvement of a neuroimmune component in apoptotic cell death after injury or chemical damage suggests that cytokines may play a role in METH effects. In the present study, we examined if the absence of IL-6 in knockout (IL-6-/-) mice could provide protection against METH-induced neurotoxicity. Administration of METH resulted in a significant reduction of [(125)I]RTI-121-labeled dopamine transporters in the caudate-putamen (CPu) and cortex as well as depletion of dopamine in the CPu and frontal cortex of wild-type mice. However, these METH-induced effects were significantly attenuated in IL-6-/- animals. METH also caused a decrease in serotonin levels in the CPu and hippocampus of wild-type mice, but no reduction was observed in IL-6-/- animals. Moreover, METH induced decreases in [(125)I]RTI-55-labeled serotonin transporters in the hippocampal CA3 region and in the substantia nigra-reticulata but increases in serotonin transporters in the CPu and cingulate cortex in wild-type animals, all of which were attenuated in IL-6-/- mice. Additionally, METH caused increased gliosis in the CPu and cortices of wild-type mice as measured by [(3)H]PK-11195 binding; this gliotic response was almost completely inhibited in IL-6-/- animals. There was also significant protection against METH-induced DNA fragmentation, measured by the number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeled (TUNEL) cells in the cortices. The protective effects against METH toxicity observed in the IL-6-/- mice were not caused by differences in temperature elevation or in METH accumulation in wild-type and mutant animals. Therefore, these observations support the proposition that IL-6 may play an important role in the neurotoxicity of METH.     

Chronic infusion of beta-adrenoceptor antagonist and inverse agonists decreases elevated protein kinase A activity in transgenic mice with cardiac-specific overexpression of human beta 2-adrenoceptor

Neutral antagonists and inverse agonists can produce different cellular responses in some systems. The effects of chronic (14-day) infusion of three ligands, ICI-118,551, carvedilol, and alprenolol were examined in cardiac tissue from wild-type and transgenic mice with cardiac-specific overexpression of the human beta2-adrenoceptor. These ligands vary in their negative efficacy at the human beta2-adrenoceptor, with two (ICI-118,551 and carvedilol) behaving as inverse agonists and one (alprenolol) behaving as a neutral antagonist. Cardiac tissue from the transgenic mice exhibited elevated levels of protein kinase A activity and G protein receptor kinase-2. Fourteen-day infusions of the three ligands lowered the elevated levels of protein kinase A activity of the transgenic hearts to control levels. Alprenolol and carvedilol also decreased G protein receptor kinase-2 amounts to control levels. The left atria from transgenic mice exhibited an impaired inotropic response to histamine relative to responses of wild-type mice atria. Infusions of the inverse agonists and a neutral antagonist at the beta2-adrenoceptor significantly restored the impaired histamine response. Restoration of protein kinase A activity and the impaired histamine responses in the atria from transgenic mice can be observed following 14-day infusions of both a neutral antagonist and inverse agonists. The reversal of the effects of the transgene by both inverse agonists and a neutral antagonist suggests that agonist occupancy, and not spontaneous activity, of the beta2-adrenoceptor is producing the elevated protein kinase A activity and the impaired histamine response.     

Chronic gastritis with expression of inducible nitric oxide synthase is associated with high expression of interleukin-6 and hypergastrinaemia

BACKGROUND AND AIMS: High levels of inducible nitric oxide synthase and nitrotyrosine in Helicobacter pylori-infected gastric mucosa may contribute to development of gastric cancer. We investigated the relation between expression of inducible nitric oxide synthase and proinflammatory cytokines in gastric mucosa and serum markers of gastritis. METHODS: The study included 103 patients with H. pylori infection. We examined levels of interleukin-1beta, interleukin-6 and interleukin-8 by enzyme-linked immunosorbent assay and evaluated expression of inducible nitric oxide synthase and nitrotyrosine by immunohistochemical staining. Furthermore, we assessed serum levels of pepsinogens, gastrin, anti-parietal cell antibody, nitrite and nitrate, as markers of gastritis. RESULTS: Thirty-seven of 103 (35.6%) gastric mucosa specimens showed simultaneous expression of inducible nitric oxide synthase and nitrotyrosine. In these patients (inducible nitric oxide synthase-positive group), the serum level of gastrin was significantly higher than that of the inducible nitric oxide synthase-negative group (509.5 +/- 141.5 pg/mL vs. 210.0 +/- 227.2 pg/mL; P < 0.01), whereas there were no significant differences in serum levels of pepsinogen, anti-parietal cell antibody, and nitrate and nitrite or in scores of histological gastritis. Interleukin-6 levels were significantly higher in the inducible nitric oxide synthase-positive group than in the inducible nitric oxide synthase-negative group (25.9 +/- 7.0 pg/mg protein vs. 10.6 +/- 4.9 pg/mg protein; P < 0.05). CONCLUSIONS: Inducible nitric oxide synthase-producing gastritis was correlated with high levels of interleukin-6. Patients with hypergastrinaemia should be carefully followed on a long-term basis to ensure that the development of any malignancy is detected early.     

Early virological suppression is associated with good maintained response to adefovir dipivoxil in lamivudine resistant chronic hepatitis B

AIM: To determine the factors affecting the virological response to adefovir dipivoxil (ADV) among patients with lamivudine resistant chronic hepatitis B. METHODS: Chronic hepatitis B virus (HBV) infected patients, who had virological relapse to lamivudine, were switched to ADV monotherapy. RESULTS: Twenty-six patients were treated by ADV for 23 (12-41) months. At baseline, the median log HBV DNA was 7.70 (4.88-9.01) copies/mL. Six (23%) and 8 (31%) of patients had HBV DNA suppressed to below 1000 copies/mL at month 12 and the last follow-up, respectively. On linear regression, patients who had higher HBV DNA at baseline and month 6 have higher HBV DNA at month 12. On Cox proportional hazard model, the hazard ratio for each log step increase in HBV DNA at baseline and month 6 for HBV DNA <1000 copies/mL at the last visit was 0.39 (P = 0.010) and 0.47 (P = 0.027), respectively. Alanine aminotransferase, HBV genotype, rtL80 M mutation and log HBsAg did not affect the HBV DNA response. CONCLUSIONS: The response of lamivudine-resistant patients to ADV is suboptimal. Treatment with ADV when HBV DNA is low, and rapid viral suppression at month 6 increases the chance of maintained viral suppression.     

Cyclooxygenase 1 is not essential for hypophagic responses to interleukin-1 and endotoxin in mice

Numerous studies have shown that the effects of interleukin-1 (IL-1) and endotoxin (LPS) on behavior are sensitive to cyclooxygenase (COX) inhibitors. However, neither the location of the COX involved nor the specific isoform, COX1 or COX2, is known. A previous study using selective COX1 and COX2 inhibitors did not provide an unequivocal answer. Therefore, we tested the response of sweetened milk ingestion to IL-1 and LPS in mice in which the COX1 or the COX2 gene was deleted (COX1ko and COX2ko). When IL-1beta was administered 90 min before the milk, COX1ko mice showed responses similar to those of normal mice. In contrast, COX2ko mice exhibited responses considerably less than normal, with some mice showing no response. Indomethacin pretreatment almost prevented the feeding responses to IL-1 in normal and COX1ko mice. The milk intake response to LPS in COX1ko mice was like that of normal mice. The results from COX1ko mice suggest that COX1 is not necessary for the decreased milk intake following IL-1 and LPS. The results from COX2ko mice are consistent with the involvement of COX2 in the IL-1-induced depression of milk intake, but other mechanisms may effect decreases in sweetened milk intake.     

Methanol teratogenicity in mutant mice with deficient catalase activity and transgenic mice expressing human catalase

The role of catalase in methanol (MeOH) teratogenesis is unclear. In rodents it both detoxifies reactive oxygen species (ROS) and metabolizes MeOH and its formic acid (FA) metabolite. We treated pregnant mice expressing either high (hCat) or low catalase activity (aCat), or their wild-type (WT) controls, with either MeOH (4 g/kg ip) or saline. hCat mice and WTs were similarly susceptible to MeOH-initiated ophthalmic abnormalities and cleft palates. aCat and WT mice appeared resistant, precluding assessment of the developmental impact of catalase deficiency. Catalase activity was respectively increased at least 1.5-fold, and decreased by at least 35%, in hCat and aCat embryos and maternal livers. MeOH and FA pharmacokinetic profiles were similar among hCat, aCat and WT strains. Although the hCat results imply no ROS involvement, embryo culture studies suggest this may be confounded by maternal factors and/or a requirement for higher catalase activity in the hCat mice.     

Effects of interleukin-1beta and lipopolysaccharide on behavior of mice in the elevated plus-maze and open field tests

It has been postulated that infections, inflammatory processes and resulting cytokines may be causative factors in emotional disorders, including depression and anxiety. Support for this possibility has been sought in studies of animal behavior following administration of interleukin-1 (IL-1) and lipopolysaccharide (LPS). However, such treatments induce a variety of behavioral responses, collectively known as sickness behavior, some of which could affect the performance in tests used to assess anxiety and depression. Thus the effects of peripheral administration of IL-1beta and LPS on the behavior of mice were studied in the elevated plus-maze (EPM) and the open field (OF). Mouse IL-1beta (30, 100, 300, and 1000 ng) was injected intraperitoneally 30 or 60 min, and LPS (0.5, 1 and 5 microg) 120 min before the tests. IL-1beta and LPS induced dose-dependent decreases in open arm entries and the time spent on the open arms in the EPM, effects considered to reflect anxiety-like behavior. However, entries to all arms were also reduced in a dose-dependent manner, indicating a decrease in general activity. In the OF, IL-1beta and LPS decreased the number of line crossings in the center of the field, that can also be considered to reflect anxiety-like behavior. However, this effect was accompanied by a similar decrease in line crossings in the periphery, as well as in rears and climbs. Thus the doses of IL-1beta and LPS necessary to induce these effects also decreased locomotor activity in the EPM and OF. Therefore, the behavioral responses induced by IL-1beta and LPS in the EPM and the OF considered to reflect anxiety must be interpreted in the light of this reduction in overall activity. Thus the results do not provide unequivocal support for the suggestion that LPS or IL-1 mediate anxiety. Nevertheless, because infections, endotoxins, and the ensuing cytokines cause alterations in CNS norepinephrine and serotonin, they may contribute to emotionality, and perhaps to anxiety.     

Increased susceptibility of low-density lipoprotein to ex vivo oxidation in mice transgenic for human apolipoprotein B treated with 1 melatonin-related compound is not associated with atherosclerosis progression

Considerable evidence supports the hypothesis that LDL oxidation has an important role in atherosclerosis. It has been demonstrated that the feeding of hypercholesterolemic mice on an atherogenic diet supplemented with melatonin highly increases the surface of atherosclerotic lesions in aorta and the sensitivity of atherogenic lipoprotein to ex vivo oxidation even though high melatonin doses inhibit lipoprotein oxidation in vitro. A melatonin-related compound (DTBHB: N-[2-(5-methoxy-1H-indol-3-yl)ethyl]-3,5-di-tert-butyl-4-hydroxybenzamide) has been reported to strongly inhibit lipid peroxidation in vitro. In the present study, DTBHB treatment considerably increased the sensitivity of atherogenic lipoproteins to ex vivo oxidation but did not modify atherosclerotic lesion development in mice. Moreover, DTBHB treatment did not induce detectable lipidic alteration. These data confirm that the capacity of molecules to inhibit atherogenic lipoprotein oxidation in vitro offers no prediction of their capacity to inhibit in vivo atherosclerosis development.     

含PreS1、PreS2和S抗原的重组乙型肝炎疫苗辅以不同佐剂在HBV转基因小鼠中的免疫原性

目的 研究以免疫刺激复合物(immune stimulating complex,ISCOM)或Al(OH)3为佐剂的含PreS1、PreS2和S抗原的重组乙型肝炎疫苗在HBV转基因小鼠中诱导的免疫应答.方法 将纯化的含PreS1、PreS2和S抗原的重组HBsAg(SS1S2)分别辅以ISCOM或Al(OH)3佐剂制成疫苗.HBV转基因小鼠每月肌内注射1针疫苗,共注射7针.免疫前及每针后1个月称量小鼠体重,观察小鼠生长情况.免疫前及每针后1个月采血,用ELISA检测HBV S、PreS1、PreS2抗原及其相应抗体.7针后1个月分离小鼠脾淋巴细胞,用酶联免疫斑点试验分别测定分泌IL-4、IL-5、IFN-γ的效应T细胞频数.结果 小鼠生长状况良好,每针后体重均有增长.首针后1个月,10只ISCOM+ SS1S2免疫鼠分别有3和1只抗S和PreS1抗体阳转,无一小鼠抗PreS2抗体阳转;10只Al(OH)3+ SS1S2免疫鼠的抗体均为阴性.7针后1个月,10只ISCOM+ SS1 S2免疫鼠的抗S和PreS1抗体均阳转,8只抗PreS2抗体阳转;10只Al(OH)3+ SS1S2免疫鼠分别有9、7和1只抗S、PreS1和PreS2抗体阳转;ISCOM+SS1S2组和Al(OH)3+ SS1S2组的抗S抗体几何平均滴度分别为1∶15 647和1∶1 039,差异有统计学意义0=5.18,P=0.000).7针后1个月,ISCOM+ SS1S2组和Al(OH)3+ SS1S2组分泌IL-4的细胞频数分别为219和78斑点形成细胞(spot-forming cell,SFC)/106细胞(t=10.50,P=0.000),分泌IL-5的细胞频数分别为286和34 SFC/106细胞(t=19.53,P=0.000),差异有统计学意义.结论 含PreS1、PreS2和S抗原的重组乙型肝炎疫苗辅以ISCOM或Al(OH)3佐剂在HBV转基因小鼠中均具有免疫原性,且ISCOM+ SS1 S2的免疫原性强于Al(OH)3+ SS1S2.     

Marinobufagenin (MBG) suppression of ethanol-seeking behavior is associated with inhibition of brain cortex Na/K-ATPase in mice.

In the present study the hypothesis was tested that sodium pump ligands (SPL) can modulate alcohol-seeking behavior and that this effect is related to changes in Na/K-ATPase activity in the central nervous system. Mice were tested for initiation of ethanol intravenous self-administration (IVSA) following i.p. pretreatment with vehicle or the endogenous SPL, marinobufagenin (MBG). Drug- and experimentally-naive mice acquired IVSA of 2% ethanol during a single 30-min session. MBG was found to dose-dependently attenuate (1.25-2.5 microg/kg) initiation of ethanol IVSA producing a decrease in the ratio and in the difference between operant responses of response-dependent and yoked animals as well as a decrease in percentage of mice demonstrating ethanol-seeking behavior. Attenuation of the reinforcing effect of ethanol resulting from MBG was associated with brain levels of this steroid capable of concurrently inhibiting Na/K-ATPase in the brain cortex. We hypothesize that endogenous digitalis-like factors could modulate the reinforcing effect of ethanol.     

酶联免疫吸附法检测病毒性肝炎患者血清白细胞介素12和肿瘤坏死因子的水平

目的测定白细胞介素12(IL-12)与肿瘤坏死因子(TNF)在病毒性肝炎患者血清中浓度。方法用双抗体夹心酶联免疫吸附法检测64例病毒性肝炎患者及20例正常对照者的血清IL-12与TNF水平。结果病毒性肝炎患者血清IL-12与TNF水平明显高于正常对照组(P<0.01);血清IL-12与TNF水平与血清总胆红素及谷丙转氨酶水平呈正相关。结论IL-12及TNF参与了病毒性肝炎的免疫病理过程,早期检测血清IL-12与TNF水平,可判断病情的严重程度及预后。     

Evidence that endogenous interleukin-1 is involved in leukocyte migration in acute experimental inflammation in rats and mice.

As a putative mediator of inflammation interleukin-1 has been implicated in the recruitment of leukocytes during the early stages of the inflammatory reaction. In the present report we have investigated the release of endogenous IL-1 in the rat zymosan pleurisy and in the mouse zymosan peritonitis. In both cases the release of the cytokine was maximal 4 hours after zymosan injection and appeared to be time-related to neutrophil migration into the inflammatory site. The effect of in vivo treatment with dexamethasone in rat pleurisy and with polyclonal anti-murine IL-1 beta antibody in mouse peritonitis was also assessed. The steroid reduced both cell migration and the release of IL-1-like activity as well as the formation of exudate and the release of eicosanoids. The anti-IL-1 beta serum inhibited selectively the number of neutrophil that migrated to the inflamed site (approximately 40%) and the IL-1 activity recovered in (approximately 70%) the exudate. In vitro incubation of the inflammatory exudate with polyclonal anti-murine IL-1 alpha or anti-murine IL-1 beta sera allowed the identification of the IL-1 species present. In the rat pleurisy IL-1 biological activity was mainly due to the alpha species, whereas IL-1 beta was the only species apparently present in the mouse peritoneal exudate.     

Metabolic syndrome is associated with severe fibrosis in chronic viral hepatitis and non-alcoholic steatohepatitis

Background The prevalence of metabolic syndrome and its possible impact on the severity of liver histological lesions have not been studied prospectively in chronic liver diseases. Aim To investigate the prevalence of metabolic syndrome in patients with chronic viral hepatitis or non‐alcoholic steatohepatitis, and to determine its associations with histological severity. Methods We prospectively included 317 patients (hepatitis B e antigen‐negative chronic hepatitis B: 95, chronic hepatitis C: 176, non‐alcoholic steatohepatitis: 46) with liver biopsy. Metabolic syndrome was defined using the Adult Treatment Panel III criteria. Histological lesions were evaluated according to Ishak’s or Brunt’s classification. Results Metabolic syndrome was present in 10.4% of patients being significantly more prevalent in non‐alcoholic steatohepatitis than in chronic viral hepatitis (41.3% vs. 5.1%, P < 0.001). In chronic viral hepatitis, cirrhosis (stages 5–6) was independently associated with increasing age, higher aspartate aminotransferase and gamma‐glutamyl‐transpeptidase levels, severe necroinflammation and metabolic syndrome (P = 0.016). In non‐alcoholic steatohepatitis, severe fibrosis (stages 3–4) was independently associated with severe necroinflammation and metabolic syndrome (P = 0.033). Presence of metabolic syndrome was not associated with presence or severity of steatosis both in chronic viral hepatitis and in non‐alcoholic steatohepatitis. Conclusion Metabolic syndrome is more prevalent in non‐alcoholic steatohepatitis than in chronic viral hepatitis; it is associated independently with more severe fibrosis but not with the severity of steatosis, both in chronic viral hepatitis and in non‐alcoholic steatohepatitis.     

Lowered serum dipeptidyl peptidase IV activity is associated with depressive symptoms and cytokine production in cancer patients receiving interleukin-2-based immunotherapy.

There is some evidence that treatment with interleukin-2 (IL-2) and interferon-alpha (IFNalpha) frequently induces depressive symptoms and activation of the inflammatory response system (IRS). There is evidence that major depression is accompanied by lowered serum activity of dipeptidyl peptidase IV (DPP IV; EC 3.4.14.5), a membrane-bound serine protease which catalyses the cleavage of some cytokines and neuro-active peptides and which modulates T cell activation and the production of cytokines, such as IL-2. This study was carried out to examine the effects of immunochemotherapy with IL-2 and IFNalpha, alone and together, in cancer patients on serum DPP IV activity in relation to changes in depressive symptoms and the IRS. The Montgomery and Asberg Rating Scale (MADRS), serum DPP IV activity, and the serum IL-6, and IL-2 receptor (IL-2R) concentrations were measured in 26 patients with metastatic cancers before and three and five days after treatment with IL-2 and IFNalpha, alone or together. Treatment with IL-2 with or without IFNalpha significantly suppressed serum DPP IV activity. The MADRS scores were significantly elevated by treatment with IL-2 with or without IFNalpha, but not IFNalpha alone. The immunochemotherapy-induced decreases in serum DPP IV were significantly and inversely correlated with the increases in the MADRS. Treatment with IL-2 alone or combined with IFNalpha also elevated serum IL-6 and IL-2R. There were significant and inverse correlations between the immuchemotherapy-induced decreases in serum DPP IV and the elevations in serum IL-6 or IL-2R. In conclusion, treatment with IL-2/IFNalpha decreases serum DPP IV activity within 3-5 days and the immunochemotherapy-induced decreases in serum DPP IV activity are significantly and inversely related to treatment-induced increases in severity of depression and signs of activation of the IRS.