Elevated cerebrospinal fluid levels of manganese superoxide dismutase in bacterial meningitis

Kinetics differ between copper-zinc and manganese superoxide dismutase activity with acute ischemic stroke

This study aimed to clarify the kinetics of copper-zinc (CuZn) and manganese (Mn) superoxide dismutase (SOD) activity in acute ischemic stroke victims. Using the nitrite method, we investigated sequential changes in CuZn and Mn SOD activity in the cerebrospinal fluid (CSF) of 8 patients with acute ischemic stroke. SOD activity in each patient was measured at 36 hours and 3, 7, 14, and 28 days after stroke. CuZn SOD activity in CSF peaked 3 days after stroke, with values gradually decreasing after 7 days. In contrast, Mn SOD activity remained significantly lower in the stroke group than in controls throughout the study. These findings may reflect differences between the 2 isoenzymes in terms of the distribution, role, and method of synthesis in brain tissue.

Profiling of superoxide dismutase isoenzymes in compartments of the developing bovine antral follicles

The antral follicle constitutes a complex and regulated ovarian microenvironment that influences oocyte quality. Oxidative stress is a cellular state that may play a role during folliculogenesis and oogenesis, although direct supporting evidence is currently lacking. We thus evaluated the expression of the three isoforms (SOD1, SOD2, and SOD3) of the enzymatic antioxidant superoxide dismutase in all the cellular (granulosa cells, cumulus cells, and oocytes) and extracellular (follicular fluid) compartments of the follicle. Comparisons were made in bovine ovaries across progressive stages of antral follicular development. Follicular fluid possessed increased amounts of SOD1, SOD2, and SOD3 in small antral follicles when compared with large antral follicles; concomitantly, total SOD activity was highest in follicular fluids from smaller diameter follicles. SOD1, SOD2, and SOD3 proteins were expressed in granulosa cells without any fluctuations in follicle sizes. All three SOD isoforms were present, but were distributed differently in oocytes from small, medium, or large antral follicles. Cumulus cells expressed high levels of SOD3, some SOD2, but no detectable SOD1. Our studies provide a temporal and spatial expression profile of the three SOD isoforms in the different compartments of the developing bovine antral follicles. These results lay the ground for future investigations into the potential regulation and roles of antioxidants during folliculogenesis and oogenesis.

Oxidative stress and S-100B protein in children with bacterial meningitis

Background

Bacterial meningitis is often associated with cerebral compromise which may be responsible for neurological sequelae in nearly half of the survivors. Little is known about the mechanisms of CNS involvement in bacterial meningitis. Several studies have provided substantial evidence for the key role of nitric oxide (NO) and reactive oxygen species in the complex pathophysiology of bacterial meningitis.

Methods

In the present study, serum and CSF levels of NO, lipid peroxide (LPO) (mediators for oxidative stress and lipid peroxidation); total thiol, superoxide dismutase (SOD) (antioxidant mediators) and S-100B protein (mediator of astrocytes activation and injury), were investigated in children with bacterial meningitis (n = 40). Albumin ratio (CSF/serum) is a marker of blood-CSF barriers integrity, while mediator index (mediator ratio/albumin ratio) is indicative of intrathecal synthesis.

Results

Compared to normal children (n = 20), patients had lower serum albumin but higher NO, LPO, total thiol, SOD and S-100B. The ratios and indices of NO and LPO indicate blood-CSF barriers dysfunction, while the ratio of S-100B indicates intrathecal synthesis. Changes were marked among patients with positive culture and those with neurological complications. Positive correlation was found between NO index with CSF WBCs (r = 0.319, p < 0.05); CSF-LPO with CSF-protein (r = 0.423, p < 0.01); total thiol with LPO indices (r = 0.725, p < 0.0001); S-100B and Pediatric Glasow Coma Scores (0.608, p < 0.0001); CSF-LPO with CSF-S-100B (r = 0.482, p < 0.002); serum-total thiol with serum S-100B (r = 0.423, p < 0.01).

Conclusion

This study suggests that loss of integrity of brain-CSF barriers, oxidative stress and S-100B may contribute to the severity and neurological complications of bacterial meningitis.

2-Methoxyestradiol-induced radiosensitization is independent of SOD but depends on inhibition of Akt and DNA-PKcs activities

BACKGROUND AND PURPOSE

2-Methoxyestradiol (2-ME) is described as an inhibitor of the superoxide dismutase (SOD) enzyme activity. However, it attenuates PI3K/Akt pathway and induces radiosensitization in human tumor cells as well. Since the activation of catalytic subunit of DNA-protein kinase (DNA-PKcs) is partially regulated by Akt activity, in the present study we investigated whether 2-ME-induced radiosensitization is dependent on inhibition of Akt and DNA-PKcs activities or on SOD targeting.

MATERIALS AND METHODS

This study was performed using the lung carcinoma cell line A549. Ionizing radiation-induced SOD activity was analyzed by superoxide dismutase activity assay. Applying Western blotting, the pattern of radiation-induced SOD expression and activation of Akt as well as DNA-PKcs was analyzed. Colony formation assay and gammaH2AX foci assay were performed to measure radiosensitization and DNA-double strand break (DNA-DSB) repair. To downregulate SOD expression small interfering RNA (siRNA) was used.

RESULTS

Irradiation with 4Gy stimulated SOD enzyme activity as early as 1min after radiation exposure. Expression of Cu/Zn-SOD (SOD1) as well as Mn-SOD (SOD2) was increased by single doses of 1-4Gy within 24-36h. 2-ME blocked radiation-induced SOD enzyme activity but not protein expression and enhanced radiation sensitivity. Pretreatment with 2-ME blocked IR-induced Akt as well as DNA-PKcs phosphorylation and impaired the repair of DNA-DSB. SiRNA targeting of SOD1 and SOD2 affected neither DNA-PKcs phosphorylation nor post-irradiation survival while inhibition of Akt by specific inhibitor abrogated 2-ME-induced radiosensitization.

CONCLUSION

These results may indicate that 2-ME-induced radiosensitization is independent of SOD inhibition but mainly depends on inhibition of Akt and DNA-PKcs activities.

Oxidative stress in cerebrospinal fluid of patients with aseptic and bacterial meningitis

This study aimed to determine whether patients with aseptic and bacterial meningitis presented alterations in oxidative stress parameters of cerebrospinal fluid (CSF). A total of 30 patients were used in the research. The CSF oxidative stress status has been evaluated through many parameters, such as lipid peroxidation through thiobarbituric acid reactive substances (TBARS) and antioxidant defense systems such as superoxide dismutase (SOD), glutathione S-transferase (GST), reduced glutathione (GSH) and ascorbic acid. TBARS levels, SOD and GST activity increase in aseptic meningitis and in bacterial meningitis. The ascorbic acid concentration increased significantly in patients with both meningitis types. The reduced glutathione levels were reduced in CSF of patients with aseptic and bacterial meningitis. In present study we may conclude that oxidative stress contributes at least in part to the severe neurological dysfunction found in meningitis.

Activities of endogenous antioxidant enzymes in the cerebrospinal fluid and the hippocampus after transient forebrain ischemia in rat

The activity of SOD and CAT was measured in controls and 5 h after 5, 10 and 15 min of ischemia, as well as 1 or 2 days after 10 min of ischemia in the hippocampus and in the CSF. A significant increase in total SOD activity 5 h after ischemia was caused mainly by increased CuZn-SOD activity. The highest values were measured 5 h after 5 min ischemia (by 160%) and smallest if 15 min (by 40%) of ischemia was used. In comparison to the hippocampus, the activity of SOD in CSF increased equally after all intervals of ischemia. Activities of total SOD and CuZn-SOD after 10 min of ischemia in the hippocampus were significantly increased only after 5 and 24 h of reperfusion but in CSF they were increased after all examined intervals of reperfusion. The activity of CAT was significantly increased in the hippocampus after 5 (by 260%), 10 and 15 min (by 100%) of ischemia. CAT activity in CSF was increased equally after all intervals of ischemia (by 200%). Ischemic attack causes a rapid response in hippocampal tissue as well as in the CSF, represented by an increase in the activity of endogenous antioxidant enzymes SOD and CAT.

A comparative study of nitric oxide, glutathione, and glutathione peroxidase activities in cerebrospinal fluid from children with convulsive diseases/children with aseptic meningitis

It has been reported that active oxygen and/or free radicals are produced in the central nervous system (CNS) compartment in patients with bacterial meningitis, so it is supposed that the levels of endogenous antioxidative scavengers in the cerebrospinal fluid (CSF) are elevated as an adaptive reaction to bacterial meningitis, which exerts severe stress on the human body. We assumed that they are also elevated in patients with convulsive diseases. Nitric oxide (NO) and endogenous antioxidative scavengers (glutathione (GSH), glutathione peroxidase (GPX), (total) superoxide dismutase (T-SOD), manganese superoxide dismutase (Mn-SOD), and catalase) were measured in CSF from a group of child patients with various neurological diseases and a control group. NO, GSH, and GPX activities in CSF from the patients with convulsive diseases were significantly higher than in those with aseptic meningitis or in the controls. Furthermore, all parameters in CSF from patients with bacterial meningitis were significantly higher than in any other group. The present study suggests that oxidative stress may be associated with the pathophysiology of convulsion and that its clinical attenuation will lead to improvement in the prognosis for convulsive diseases.

[Oxidative profile of tonsil infection. Study of antioxidant enzymes in tonsil and blood]

In order to investigate the effect of oxidative damage due to free radicals on ENT infectious diseases, levels of superoxide dismutase (SOD), glutathione-peroxidase (GPx) and reductase (GRt) and the total antioxidant status (TAS) were measured by spectrophotometry on tonsillar tissue obtained from tonsillectomy in 538 patients, who were divided in three groups according to their surgical indication: tonsillar hypertrophy (n = 235), recurrent tonsillitis (n = 280) or peritonsillar abscess (n = 23). SOD concentration were also measured on adenoid tissue and middle ear exudate in 75 patients from the first two groups. Erythrocyte and tonsillar SOD levels were significantly greater in the abscess group, and lower in the hypertrophic one. These differences were similar for GPx and TAS. For GRt, its level in abscess were lower than in the other two groups in a statistically significant way. There were strong correlations between erythrocyte and tonsillar SOD, tonsillar SOD and GPx, tonsillar SOD and TAS, and tonsillar GPx and TAS. SOD concentrations from adenoid tissue and middle ear exudate did not affect its blood level. So, we can conclude that tonsillar oxidative damage is determined by the frequency or the severity of local infections, and it can be evaluated by measuring the SOD concentration in the tonsillar tissue or in the peripheral blood. So, it can be considered a good marker of tonsillar damage.

Immunocytochemical demonstration of the expression and induction of manganese-superoxide dismutase in the adenohypophysis

Immunocytochemistry for manganese-superoxide dismutase (Mn-SOD) was studied in 12 normal adenohypophyses and 38 various pituitary lesions. The proportions of cells with granular immunoreactivity for Mn-SOD in normal adenohypophysis ranged from 9.8% to 29.6% (mean +/- SD; 18.4+/-6.2%). Some positive cells tended to accumulate in clusters, distribution of which corresponded well with those immunopositive for mitochondrial protein and cytochrome oxidase. The number of Mn-SOD-positive cells increased in adjacent residual adenohypophysis in eight of nine recent infarcts, in two of five old infarcts, in all four cases of lymphocytic hypophysitis, in two of four abscess cases and in one of three metastatic tumour cases, whereas the immunoreactivities of mitochondrial protein- and cytochrome oxidase-positive cells either did not vary or decreased. The intensity of the histological inflammatory reactions showed a positive correlation with reactivity for Mn-SOD in these lesions. Of eight adenomas, the surrounding area of compressed adenohypophysis showed increased numbers of Mn-SOD- and mitochondrial protein-/cytochrome oxidase-positive cells in four and six cases respectively. It is suggested that positivity for Mn-SOD may be related to some functional activity of mitochondria. It is further suggested that adenohypophysial cells have a high potential to induce Mn-SOD by inflammatory and ischaemic stress and, in addition, by enhanced mitochondrial activity.