Overexpression of mTOR in Leukocytes from ALS8 Patients.

BACKGROUND: The mutated VAPBP56S (vesicle B associated membrane protein - P56S) protein has been described in a Brazilian family and classified as Amyotrophic Lateral Sclerosis type 8 (ALS8). OBJECTIVE: We aimed to study altered biochemical and immunological parameters in cells from ALS8 patients to identify possible biomarkers or therapeutic targets. METHODS: Wild-type VAPB, VAPBP56S, mTOR, proinflammatory cytokines, and oxidant/reducing levels in serum, leucocytes, and cellular lysate from ALS8 patients and health Controls were performed by ELISA, fluorimetry, and spectrophotometry. RESULTS: Our results showed similar levels of mutant and wild-type VAPB in serum and intracellular lysate (p > 0.05) when ALS8 patients and Controls were compared. IL-1ß, IL-6, and IL-18 levels in patients and Controls showed no difference, suggesting an absence of peripheral inflammation (p > 0.05). Oxidative metabolic response, assessed by mitochondrial ROS production, and reductive response by MTT reduction, were higher in the ALS8 group compared to Controls (p < 0.05), although not characterizing typical oxidative stress in ALS8 patients. Total mTOR levels (phosphorylated or non-phosphorylated) of ALS8 patients were significantly lower in serum and higher in intracellular lysate than the mean equivalents in Controls (p < 0.05). A similar result was observed when we quantified the phosphorylated protein (p < 0.05). CONCLUSION: We demonstrate the possibility of using these biochemical and immunological parameters as potential therapeutic targets or biomarkers. Furthermore, by hypothesis, we suggest a hormetic response in which both VAPB forms could coexist in different proportions throughout life. The mutated VAPBP56S production would increase with aging and predominate over the wild-type VAPB levels, determining the onset of symptoms and aggravating the disease.

Edaravone Inhibits the Production of Reactive Oxygen Species in Phagocytosis- and PKC-Stimulated Granulocytes from Multiple Sclerosis Patients Edaravone Modulate Oxidative Stress in Multiple Sclerosis.

Background: Oxidative stress is associated with the pathogenesis of MS. Edaravone (EDV) has been proposed as a therapeutic resource for central nervous system diseases, and it was effective in reducing oxidative stress. However, the antioxidant mechanisms of EDV are poorly studied. Objective: This study aimed to evaluate the effects of EDV on resting, phagocytosis, and PKC-activated granulocytes derived from MS patients and a healthy control group. Methods: The effects of EDV on ROS production in phagocytosis (ROS production in the presence of opsonized particles) and PKC-stimulated granulocytes were evaluated in a luminol-dependent chemiluminescence method. Calphostin C was used in some experiments to compare with those of EDV. Results: EDV inhibited ROS production in phagocytosis of opsonized particles and PKC-stimulated granulocytes from MS patients and healthy control group. In the presence of calphostin C, the inhibition of ROS production was similar to that observed with EDV. Conclusion: These findings suggest the involvement of EDV on the ROS-PKC-NOX signaling pathways modulating oxidative stress in MS. EDV represents a promising treatment option to control oxidative innate immune response for MS.

IL-6, IL-1ß and MDA correlate with Thrombolysis in Myocardial Infarction (TIMI) risk score in patients with Acute Coronary Syndrome.

BACKGROUND: Inflammation plays a significant role in the pathophysiology of Acute Coronary Syndrome (ACS) but is not included in current risk stratification. OBJECTIVE: To determine the association between Thrombolysis in Myocardial Infarction (TIMI) risk score and inflammatory biomarkers in the ACS, including unstable angina (UA), non-ST segment elevation myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI). We hypothesized that including inflammatory biomarkers could add prognostic value to the TIMI risk score. METHODS: In this cross-sectional study, serum levels of interleukins (IL)-6 and IL-1ß and MDA (malondialdehyde) were quantified by ELISA and colorimetry, respectively , patients with ACS (n = 48; 31.3% with UA, 33.3% with NSTEMI, and 35.4% with STEMI) and healthy controls (n = 43). We assessed the TIMI scores in the first 24 h after symptom onset. RESULTS: The results showed that patients with ACS had significantly higher levels (p<0.05) of the inflammatory biomarkers IL-6, IL-1ß, and MDA compared to the control group. However, we found no significant differences in IL-6, IL-1ß, and MDA levels among the patients with ACS according to their classification as UA, NSTEMI, and STEMI. Positive correlations were observed between TIMI and IL-6 (r=0.68), IL-1ß (r= 0.53), and MDA (r=0.58) in patients with UA and between TIMI and IL-1ß (r= 0.62) in STEMI patients. CONCLUSION: These data suggest the presence of a pro-inflammatory profile in patients with ACS as well as positive correlations between TIMI scores and the inflammatory biomarkers IL-6, IL-1ß, and MDA in patients with UA and between TIMI scores and IL-1ß in patients with STEMI. Combining inflammatory biomarkers with the TIMI risk score could provide better insight into the processes involved in ACS.

Association between thrombomodulin and high mobility group box 1 in sepsis patients.

BACKGROUND: High mobility group box 1 (HMGB1) has been studied as a molecule associated with severe outcomes in sepsis and thrombomodulin (TM) seems to decrease HMGB1 activity. AIM: To investigate the role of the thrombomodulin/high mobility group box 1 (T/H) ratio in patients with sepsis and their association with their clinic, testing the hypothesis that higher ratios are associated with better outcomes. METHODS: Twenty patients diagnosed with sepsis or septic shock, according to the 2016 criteria sepsis and septic shock (Sepsis-3), were studied. Patients were followed until they left the intensive care unit or until they achieved 28 d of hospitalization (D28). The following clinical outcomes were observed: Sequential Organ Failure Assessment (SOFA) score; Need for mechanical pulmonary ventilation; Presence of septic shock; Occurrence of sepsis-induced coagulopathy; Need for renal replacement therapy (RRT); and Death. RESULTS: The results showed that patients with SOFA scores greater than or equal to 12 points had higher serum levels of TM: 76.41 ± 29.21 pg/mL vs 37.41 ± 22.55 pg/mL among those whose SOFA scores were less than 12 points, P = 0.003. The T/H ratio was also higher in patients whose SOFA scores were greater than or equal to 12 points, P = 0.001. The T/H ratio was, on average, three times higher in patients in need of RRT (0.38 ± 0.14 vs 0.11 ± 0.09), P < 0.001. CONCLUSION: Higher serum levels of TM and, therefore, higher T/H ratio in the first 24 h after the diagnosis of sepsis were associated with more severe disease and the need for renal replacement therapy, while those with better clinical outcomes and those who were discharged before D28 showed a tendency for lower T/H ratio values.

Is Galanin a Promising Therapeutic Resource for Neural and Nonneural Diseases?

BACKGROUND: Galanin (GAL) constitutes a family of neuropeptides composed of four peptides: (i) galanin (GAL), (ii) galanin-message associated peptide (GAMP), (iii) galanin-like peptide (GALP), and (iv) alarin. GAL contains 29/30 amino acids, and its biological action occurs through the interactions with its various receptors (GALR1, GALR2, and GALR3). The neuropeptide GAL regulates several physiological and pathophysiological functions in the central nervous system, the peripheral nervous system, and the peripheral organs. GAL is secreted mainly by oligodendrocytes, astrocytes, and the gastrointestinal tract, and its effect depends on the interaction with its different receptors. These receptors are expressed mainly in the central, peripheral nervous systems and the intestines. OBJECTIVE: The present review evaluates the role of GAL family in inflammatory diseases. An overview is given of the signaling and pharmacological effects due to the interaction between GAL and GALR in different cell types. The potential use of GAL as a therapeutic resource is critically discussed. CONCLUSION: GAL is suggested to have an anti-inflammatory function in some situations and a proinflammatory function in others. The literature on GAL is controversial and currently not conclusive. This could be due to the complexity of the metabolic network signaling induced by the interactions between GAL and GALR. In the next future, GAL might be a promising therapeutic resource for several diseases, but its practical use for disease control is presently not advisable.

Effects of immunotherapy induction on outcome and graft survival of kidney-transplanted patients with different immunological risk of rejection.

BACKGROUND: In kidney transplantation, immunotherapy with thymoglobulin (rATG) has been used to down-regulate the patient immune system. rATG is a powerful immunobiologic drug used to deplete lymphocytes to prevent early acute rejection. The aim of this research was to evaluate the effects of immunotherapy by rATG on graft suvival during a 9-year period in kidney-transplanted patients with different immunological profiles. METHODS: A sample of 469 patients were allocated into four groups (G) based on immunological risk of rejection: G1, low risk, not sensitized recipients, solid-phase immunoassay with single antigen beads (SPI-SAB) < 10%; G2, medium risk I, sensitized recipients, SPI-SAB ≥ 10 < 50%; G3, medium risk II sensitized (SPI-SAB ≥50%); and G4, high risk, sensitized recipients, SPI-SAB- donor-specific antibody positive (DSA+). Only patients from G3 and G4 received immunotherapy. RESULTS: Of 255 patients who received a kidney from a living donor (LD), 42 (16.47%) from all groups (G) had T-cell-mediated rejection (TCMR) and four (G1) lost their grafts, 8 (3.14%) had antibody-mediated rejection (AMR), and two lost their graft in G1 and G4. Of 214 patients who received a kidney from deceased donors (DD), 37 (17.29%) had TCMR with one lost graft in G1. AMR was shown in 13 (6.07%) patients, with three losses observed in G2. Statistical differences between the groups in the 9-year graft survival rate were found only in the comparison of G1 versus G2 (P = 0.005) and G2 versus G4 (P = 0.047) for DD. For LD, no statistical differences were found. CONCLUSION: This clinical retrospective study shows that immunotherapy induction was associated with improvement of outcomes, graft function, and survival in patients treated with immunotherapy in comparison with patients who did not received induction therapy. These findings strongly suggest that immunotherapy should be used for all patients transplanted with kidneys from deceased donors.

Cellular death, reactive oxygen species (ROS) and diabetic complications.

Chronic or intermittent hyperglycemia is associated with the development of diabetic complications. Several signaling pathways can be altered by having hyperglycemia in different tissues, producing oxidative stress, the formation of advanced glycation end products (AGEs), as well as the secretion of the pro-inflammatory cytokines and cellular death (pathological autophagy and/or apoptosis). However, the signaling pathways that are directly triggered by hyperglycemia appear to have a pivotal role in diabetic complications due to the production of reactive oxygen species (ROS), oxidative stress, and cellular death. The present review will discuss the role of cellular death in diabetic complications, and it will suggest the cause and the consequences between the hyperglycemia-induced signaling pathways and cell death. The signaling pathways discussed in this review are to be described step-by-step, together with their respective inhibitors. They involve diacylglycerol, the activation of protein kinase C (PKC) and NADPH-oxidase system, and the consequent production of ROS. This was initially entitled the "dangerous metabolic route in diabetes". The historical usages and the recent advancement of new drugs in controlling possible therapeutical targets have been highlighted, in order to evaluate the evolution of knowledge in this sensitive area. It has recently been shown that the metabolic responses to stimuli (i.e., hyperglycemia) involve an integrated network of signaling pathways, in order to define the exact responses. Certain new drugs have been experimentally tested-or suggested and proposed-for their ability to modulate the possible biochemical therapeutical targets for the downregulation of retinopathy, nephropathy, neuropathy, heart disease, angiogenesis, oxidative stress, and cellular death. The aim of this study was to critically and didactically evaluate the exact steps of these signaling pathways and hence mark the indicated sites for the actions of such drugs and their possible consequences. This review will emphasize, besides others, the therapeutical targets for controlling the signaling pathways, when aimed at the downregulation of ROS generation, oxidative stress, and, consequently, cellular death-with all of these conditions being a problem in diabetes.

The production of nitric oxide, IL-6, and TNF-alpha in palmitate-stimulated PBMNCs is enhanced through hyperglycemia in diabetes.

We examined nitric oxide (NO), IL-6, and TNF-α secretion from cultured palmitate-stimulated PBMNCs or in the plasma from type 2 diabetes mellitus (T2MD) patients or nondiabetic (ND) controls. Free fatty acids (FFA) have been suggested to induce chronic low-grade inflammation, activate the innate immune system, and cause deleterious effects on vascular cells and other tissues through inflammatory processes. The levels of NO, IL-6, TNF-α, and MDA were higher in supernatant of palmitate stimulated blood cells (PBMNC) or from plasma from patients. The results obtained in the present study demonstrated that hyperglycemia in diabetes exacerbates in vitro inflammatory responses in PBMNCs stimulated with high levels of SFA (palmitate). These results suggest that hyperglycemia primes PBMNCs for NO, IL-6, and TNF-alpha secretion under in vitro FFA stimulation are associated with the secretion of inflammatory biomarkers in diabetes. A combined therapy targeting signaling pathways activated by hyperglycemia in conjunction with simultaneous control of hyperglycemia and hypertriglyceridemia would be suggested for controlling the progress of diabetic complications.

Vitamin complex (ascorbic acid, alpha-tocopherol and beta-carotene) induces micronucleus formation in PBMNC unrelated to ROS production.

OBJECTIVES: To evaluate the correlation between reactive oxygen species (ROS) production and micronucleus formation induced by a vitamin complex in peripheral blood mononuclear cells from healthy people aged between 40 and 85 years old. METHODS: Peripheral blood mononuclear cells (PBMNCs) were purified utilizing ficoll-hypaque gradient. ROS production by PBMNCs was quantified by luminol-dependent chemiluminescence in the presence or in the absence of the vitamin complex. DNA damage in PBMNC by the vitamin complex was detected by the micronucleus technique. Statistical analyses were made with the Student's 't' test and the Pearson correlation. P < 0.05 was considered significant. RESULTS: The vitamin complex induced MN formation in PBMNC but did not augment ROS production. There was no correlation between ROS production and MN formation either in the presence or in the absence of the vitamin complex. DISCUSSION: There was no increase in the ROS production in the presence of the vitamin complex. The vitamin complex induced an augmentation in the MN formation. There was no correlation between ROS production and the induction of MN formation. Since no association could be detected between ROS production and MN formation, additional studies are required in order to investigate the possible mechanism of vitamin-induced MN formation.

ß-Carotene, α-tocopherol and ascorbic acid: differential profile of antioxidant, inflammatory status and regulation of gene expression in human mononuclear cells of diabetic donors.

BACKGROUND: Diabetic patients are exposed to increased oxidative stress due to several mechanisms, mainly hyperglycaemia. Pathological processes, such as those in type 1 diabetes, include diminished activity of the antioxidant defense system(s) or excessive oxidative generation resulting in an oxidative/antioxidant imbalance and development of oxidative stress. METHODS: The purpose of this study was to evaluate the production of reactive oxygen species (ROS) (chemiluminescence) and reduction capacity (MTT dye reduction), the expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits, superoxide dismutase and catalase using quantitative reverse-transcriptase polymerase chain reaction, and the levels of cytokines [interleukin (IL)-6, tumour necrosis factor-α, IL-8, IL-10 and IL-4] by sandwich enzyme-linked immunosorbent assay in mononuclear cells from non-diabetic and diabetic donors treated with a vitamin complex (ascorbic acid, ß-carotene and α-tocopherol) in two different concentrations ([A] = ascorbic acid = 0.08 µM, α-tocopherol = 0.04 µM, ß-carotene = 0.0008 µM and [20A] = ascorbic acid = 1.6 µM, α-tocopherol = 0.82 µM, ß-carotene = 0.016 µM). RESULTS: Concentration [A] was antioxidant reducing ROS production, expression of NADPH oxidase subunits and pro-inflammatory cytokines while raising the expression of antioxidant enzymes and reducing pro-inflammatory cytokines in both groups. Concentration [20A] was pro-oxidant by raising ROS production, NADPH oxidase subunits and pro-inflammatory cytokines and reducing antioxidant enzymes and anti-inflammatory cytokines in the non-diabetic group but antioxidant in cells of type 1 diabetic patients by raising antioxidant enzymes and anti-inflammatory cytokines and reducing pro-inflammatory cytokines. CONCLUSION: The vitamin complex has a dual effect, pro-oxidant and antioxidant, being also dose dependent with different profiles of cells of non-diabetic and type 1 diabetic patients.

The role of L-arginine-nitric oxide pathway in bacterial translocation.

This study investigated the nitric oxide (NO) role as a mediator of arginine on bacterial translocation (BT) and gut damage in mice after intestinal obstruction (IO). The effects of pretreatment with arginine with or without NO inhibition on the systemic and local immunological response were also assessed. Mice were categorized into four groups. Group ARG received chow containing 2 % arginine, while group ARG + L-NAME received the same diet plus L-NAME (N-nitro-L-arginine methyl ester) by gavage. The IO and Sham groups were fed standard chow. After 7 days, animals were gavaged with radiolabeled Escherichia coli, anesthetized and subjected to IO, except the Sham group. Animals were euthanized after 18 h, and BT was evaluated in the mesenteric lymph nodes, blood, liver, spleen and lungs. In another experiment, the intestinal injury was assessed regarding intestinal permeability and ileum histological analyses. Intestinal secretory immunoglobulin A (sIgA) levels, serum IFN-γ and IL-10 cytokines were assessed. Arginine reduced BT, but NO inhibition enhanced BT compared with the ARG group (p < 0.05). Intestinal permeability in the ARG and ARG + L-NAME groups was similar but decreased when compared with the IO group (p < 0.05). Histological preservation was observed. Arginine treatment increased IL-10 and sIgA levels when compared with the Sham and IO groups (p < 0.05). The cytokines and sIgA concentrations were similar in the ARG + L-NAME and Sham groups. Arginine appeared to reduce BT and its effects on the modulation of cytokines and secretory IgA in mice after IO are mediated by NO production.

Suppressive effect of aqueous humor from person with type 2 diabetes with or without retinopathy on reactive oxygen species generation.

AIM: To evaluate the antioxidant capacity and concentrations of vascular endothelial growth factor (VEGF) and interleukin 6 (IL-6) in aqueous humor from patients with type 2 diabetes mellitus (T2DM) with or without retinopathy. METHODS: Aqueous humor was obtained during elective cataract surgery from T2DM patients with or without retinopathy and from healthy subjects. Reducing response was evaluated by MTT dye reduction and the generation of reactive oxygen species (ROS) was determined by chemiluminescence assay. Granulocytes were treated with phorbol dibutyrate (PDB)-stimulated. Cytokines were quantified by ELISA. RESULTS: Antioxidant capacity of aqueous humor from patients with retinopathy was greater (P<0.05) than that of healthy controls or persons with diabetes without retinopathy. ROS production in PDB (protein kinase C activator)-stimulated granulocytes from T2DM patients with or without retinopathy was inhibited by autologous aqueous humor. Concentrations of VEGF and IL-6 were similar in aqueous humor from healthy controls and from patients without retinopathy, but lower (P<0.05) than those from T2DM patients with retinopathy. Plasma levels of VEGF and IL-6 were similar (P>0.05) in healthy controls and in T2DM patients with and without retinopathy. CONCLUSION: Aqueous humor from T2DM patients with retinopathy exhibits elevated antioxidant activity with significant suppressive effect on ROS production and enhanced levels of locally secreted VEGF and IL-6 in comparison with T2DM patients without retinopathy. These results suggest an inflammatory profile in the absence of typical oxidative stress for T2DM patients with retinopathy, possibly resulting from the compensatory antioxidant response detected in the aqueous humor improving the ocular redox state.

High doses of in vitro beta-carotene, alpha-tocopherol and ascorbic acid induce oxidative stress and secretion of IL-6 in peripheral blood mononuclear cells from healthy donors.

BACKGROUND: Oxidative stress represents an imbalance between the production and manifestation of reactive oxygen species (ROS) and a biological system's ability to readily detoxify the reactive intermediates or repair the resulting damage. Our objective was to verify the existence of an in vitro dual effect of alpha-tocopherol, beta-carotene and ascorbic acid in peripheral blood mononuclear cells (PBMNC) of healthy donors and the inflammatory capacity by IL-6 production. METHODS: PBMNC were incubated with two concentrations of vitamin complex: [A] = Ascorbic Acid = 0.08µM, α- tocopherol = 0.04µM, ß-carotene = 0.0008 µM and [20A] = Ascorbic Acid = 1.6µM, α-tocopherol = 0.82µM, ß-carotene = 0.016µM. Oxidizing and reducing response were measured by chemiluminescence and MTT assays, respectively. IL-6 production was measured by sandwich ELISA. RESULTS: Ours results demonstrated that PBMNC (from 20-39-year-old donors) incubated with vitamins activated free radical production only in [20A] concentration. However, in the age groups of 40-59 and 60-80 years old, there was a significant reduction and activation of the oxidizing response with both concentrations, respectively. The inflammatory profile showed an elevation of IL-6 production in pro-oxidant and a decrease in antioxidant conditions. Correlation between ROS production and IL-6 releasing was observed. CONCLUSIONS: With this experiment we concluded that vitamins can exert an antioxidant effect and a pro-oxidant effect according to their concentration, and could be an inductor of an inflammatory process in vitro generating severe complications to the body in cellular levels.

Ascorbic acid, alpha-tocopherol, and beta-carotene reduce oxidative stress and proinflammatory cytokines in mononuclear cells of Alzheimer's disease patients.

OBJECTIVES: The in vitro effect of a vitamin complex in generating and reducing oxidative species in peripheral blood mononuclear cells (PBMNC) and plasma of patients with Alzheimer's disease (AD) and healthy subjects (HS) was evaluated. METHODS: Two concentrations of a vitamin complex ([A] and [20A]) with ascorbic acid, alpha-tocopherol, and beta-carotene were incubated with either mononuclear cells or plasma. The generation of oxidizing species was measured in a luminol-dependent chemiluminescence assay and the reducing response by the MTT dye reduction assay. The levels of cytokines (interleukin [IL]-1ß, IL-6, and IL-4) were measured by sandwich enzyme-linked immunosorbent assay. RESULTS: Our results demonstrated that the increase in the vitamin complex concentration reduced the reactive oxygen species (ROS) production and enhanced cellular reduction capacity in cells of AD patients in concentration [20A]. Plasma reduction capacity rose significantly for both groups (AD and HS). Concentration [A] did not alter the IL-1ß production, increased IL-4 production in both groups and lowered IL-6 production in AD cells. Concentration [20A] increased pro-inflammatory cytokines (IL-1ß and IL-6) and decreased IL-4 production by PBMNC of HS leading to a pro-inflammatory status. DISCUSSION: The antioxidant vitamin complex was effective in reducing oxidative stress in PBMNC of AD patients by lowering ROS production, improving cellular antioxidant capacities and modifying cytokine induced inflammation.

HMGB1, TLR and RAGE: a functional tripod that leads to diabetic inflammation.

INTRODUCTION: Despite advances in treatment of diabetes mellitus, its prevalence continues to rise globally. Medications available are unable to control the vascular complications. Proposals for new therapeutic targets must take into account the hyperglycemia-induced signaling pathways that give rise to the inflammatory profile of the disease. AREAS COVERED: How high-mobility-group box-1 (HMGB1) protein, acting as an activator of Toll-like receptors (TLR) and receptors for advanced glycation end products (RAGE), creates a functional tripod that contributes to increased production of pro-inflammatory mediators, and sustains the chronic inflammatory state associated with diabetes. The interaction of TLR2 and TRL4 with host-derived ligands, which links diabetic complications with the innate immune response, and the activation of RAGE, which induces a cascade of metabolic responses, leading to the production and secretion of pro-inflammatory cytokines. EXPERT OPINION: Considering the involvement of the innate immune system, in association with the role of HMGB1 as an activator of TLR and RAGE, diabetes should be considered and treated as a metabolic and immunological disease, triggered by hyperglycemia. HMGB1 plays a central role in mediating injury and inflammation, and interactions involving HMGB1-TLR-RAGE constitute a tripod that trigger NF-κB activation. Blockade or downregulation of HMGB1, and/or control of the inflammatory tripod, represent a promising therapeutic approach for the treatment of diabetes.

The role of oxidative stress in the aging process.

The aging of organisms is characterized by a gradual functional decline of all organ systems. An appropriate theory must explain four main characteristics of aging: it is progressive, endogenous, irreversible, and deleterious for the individual. The aging of the immune system, or immunosenescence, is manifested by an increased susceptibility to infections with increased morbidity and mortality. Phagocytic capacity, synthesis of reactive oxygen intermediaries, and the intracellular killing efficiency of neutrophils are impaired in the elderly. Among all aging theories, the most updated one describes the free radicals. It implies that progressive aging is associated with higher levels of oxidative biomolecules reacted with free radicals. Although reactive oxygen species (ROS) are predominantly implicated in causing cell damage, they also play a major physiological role in several aspects of intracellular signaling and regulation. ROS include a number of chemically reactive molecules derived from oxygen. Not only oxygen, but also nitrogen can be deleterious species. The overproduction of reactive nitrogen species (RNS) is called nitrosative stress. ROS/RNS are known to play a dual role in biological systems since they can be either harmful or beneficial to living systems.

Role PKA and p38 MAPK on ROS production in neutrophil age-related: Lack of IL-10 effect in older subjects.

BACKGROUND: There is a large increase in the number of elderly people in modern societies. This demographic phenomenon has been paralleled by an epidemic of chronic diseases and inflammatory processes usually associated with advanced age. OBJECTIVE: We studied the role of protein kinase A (PKA), protein kinase B (Akt/PKB) and p38 mitogen-activated protein kinase (p38 MAPK) signaling pathways in ROS produced by neutrophils induced by pro-interferon-gamma (IFN-gamma) or anti-inflammatory interleukin 10 (IL-10) cytokines age-related. METHODS: The ROS generation was studied in healthy subjects in age ranging from 20 to 80 years old divided in five age groups: (20-39), (40-49), (50-59), (60-69) and (70-80) years old. ROS production was quantified in a luminol-dependent chemiluminescence assay and the results were expressed as relative light units/min). RESULTS: ROS production in human neutrophil was activated by IFN-gamma in all the groups studied. This activation was down-regulated by IL-10. The inhibitory effect of IL-10 on 20-49 years old group was reversed by the pre-treatment with H89 (PKA inhibitor) but not with PD169316 (p38 MAPK inhibitor). This differential effect of IL-10 associated with age was not observed with the neutrophil pre-treatment with Akt/PKB or NADPH-oxidase inhibitor (DPI). Lack of IL-10 effect on ROS production was observed in older subjects (50-80 years old). The effect of IL-10 showed a significant inhibition of ROS production similar to those got with PD169316 alone as compared to that of p38 MAPK. CONCLUSION: The results suggest that inhibitory effect of the ROS production mediated by IL-10 depends on PKA for the younger and the lack effect on the elderly is p38 MAPK dependent.

cAMP activates the generation of reactive oxygen species and inhibits the secretion of IL-6 in peripheral blood mononuclear cells from type 2 diabetic patients.

Peripheral blood mononuclear cells (PBMNC) from patients with type 2 diabetes (DM2) have generated higher levels of reactive oxygen species (ROS) that were higher than those in cells from healthy individuals. In the presence of a cAMP-elevating agent, ROS production was significantly activated in PBMNC from DM2 patients but it was inhibited in cells from healthy subjects. Higher levels of IL-6 has been detected in the supernatant of PBMNC cultures from DM2 patients in comparison with healthy controls. When cells were cultured in the presence of a cAMP-elevating agent, the level of IL-6 decreased has by 46% in the supernatant of PBMNC from DM2 patients but it remained unaltered in controls. No correlations between ROS and IL-6 levels in PBMNC from DM2 patients or controls have been observed. Secretions of IL-4 or IFNgamma by PBMNC from patients or controls have not been affected by the elevation of cAMP. cAMP elevating agents have activated the production of harmful reactive oxidant down modulated IL-6 secretion by these cells from DM2 patients, suggesting an alteration in the metabolic response possibly due to hyperglicemia. The results suggest that cAMP may play an important role in the pathogenesis of diabetes.

[Oxidative stress: a review on metabolic signaling in type 1 diabetes]. / Estresse oxidativo: revisão da sinalização metabólica no diabetes tipo 1.

Diabetic complications appear to be multifactorial process. The biochemical and pathological mechanisms are associated with chronic hyperglycemia of diabetes and the increased oxidative stress which has been postulated to play a central role in these disorders. Accumulating evidence suggests that oxidative cell injury caused by free radicals contributes to the development of type 1 diabetes (DM1) complications and decreased efficiency of antioxidant defenses (both enzymatic and nonenzymatic) seems to correlate with the severity of pathological tissue changes in DM1. In this review, we report as oxidative stress may exert deleterious effects in diabetes, as well as address current strategies in study to down-regulating vascular injury.

Estresse oxidativo: revisão da sinalização metabólica no diabetes tipo 1 / Oxidative stress: a review on metabolic signaling in type 1 diabetes

O diabetes melito e suas complicações apresentam origem multifatorial. Mecanismos bioquímicos e patológicos estão associados com hiperglicemia crônica no diabetes e o aumento do estresse oxidativo tem sido postulado com papel central nestas desordens. Evidências sugerem que a lesão celular oxidativa causada pelos radicais livres contribuem para o desenvolvimento das complicações no diabetes tipo 1 (DM1) e a diminuição das defesas antioxidantes (enzimáticas e não-enzimáticas) parecem correlacionar-se com a gravidade das alterações patológicas no DM1. Nesta revisão, relata-se como o estresse oxidativo pode exercer efeitos deletérios no diabetes e são apresentadas as opções terapêuticas em estudo para modulação da injúria vascular.

Diabetic complications appear to be multifactorial process. The biochemical and pathological mechanisms are associated with chronic hyperglycemia of diabetes and the increased oxidative stress which has been postulated to play a central role in these disorders. Accumulating evidence suggests that oxidative cell injury caused by free radicals contributes to the development of type 1 diabetes (DM1) complications and decreased efficiency of antioxidant defenses (both enzymatic and nonenzymatic) seems to correlate with the severity of pathological tissue changes in DM1. In this review, we report as oxidative stress may exert deleterious effects in diabetes, as well as address current strategies in study to down-regulating vascular injury.