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-1β 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-1β 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-1β, and MDA compared to the control group. However, we found no significant differences in IL-6, IL-1β, 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-1β (r= 0.53), and MDA (r=0.58) in patients with UA and between TIMI and IL-1β (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-1β, and MDA in patients with UA and between TIMI scores and IL-1β in patients with STEMI. Combining inflammatory biomarkers with the TIMI risk score could provide better insight into the processes involved in ACS.

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.

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.

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.

Oxidative stress and interleukin-6 secretion during the progression of type 1 diabetes

OBJECTIVE: To evaluate inflammatory, oxidizing, and reducing responses during the progression of type 1 diabetes mellitus (T1DM) in patients without chronic complications. SUBJECTS AND METHODS: Plasma antioxidant status, reactive oxygen species (ROS), and interleukin-6 (IL-6) were measured in 42 patients with T1DM and in 24 healthy subjects. RESULTS: Significant increases were detected in the median values of ROS and IL-6 in patients with T1DM compared with healthy subjects (ROS ~ 4,836 vs. 2,036 RLU/min, respectively; P < .05: IL-6 ~ 14.2 vs. 9.7 pg/mL, respectively; P = .002). No significant between-group differences (P > 0.05) were observed in oxidizing responses or in IL-6 concentrations when diabetic patients were grouped according to time after diagnosis (0 - 10, 10 - 20 and > 20 years). Plasma antioxidant responses were similar in patients with T1DM and in healthy subjects. CONCLUSIONS: Our results demonstrate that oxidizing and inflammatory responses are increased at the onset of T1DM, but remain unchanged during disease progression. These findings suggest that functional changes involved in diabetic complications may commence in the first years after diagnosis.