Caffeic Acid Phenethyl Ester Exerts a Neuroprotective Effect on CNS Against Pentylenetetrazol-Induced Seizures in Mice

Since overexcitation of excitatory amino acid is an important mechanism in seizure genesis wherein free radicals have recently been suggested to play a critical role, we explored the effects of caffeic acid phenethyl ester (CAPE) administration in pentylenetetrazole (PTZ)-induced seizure in mice. CAPE prevents the oxidative damage in brain tissue induced by PTZ, scavenging reactive oxygen species (ROS). Our results demonstrate that CAPE treatment which prevents free radical production and ameliorates seizure severity may be useful at least as an adjunctive treatment of seizure disorders.     

Caffeic acid phenethyl ester suppresses oxidative stress in Escherichia coli-induced pyelonephritis in rats

Although oxidative damage is known to be involved in inflammatory-mediated tissue destruction, modulation of oxygen free radical production represents a new approach to the treatment of inflammatory diseases. Caffeic acid phenethyl ester (CAPE), an active component of propolis from honeybee hives, has antioxidant, anti-inflammatory and antibacterial properties. For that reason, we aimed to investigate the efficiency of CAPE administration in preventing oxidative damage in pyelonephritis (PYN) caused by Escherichia coli. In this study, 35 Wistar rats were grouped as follows: control, PYN 24 h, PYN 48 h, PYN 72 h, CAPE 24 h, CAPE 48 h and CAPE 72 h. E. coli (1 × 10⁹ c.f.u.) were inoculated into the rats in both PYN and CAPE groups via urethral catheterization. Ten μM/kg-body weight CAPE was injected to the rats in all CAPE groups 24 h before E. coli infection, and injections were repeated at 24-h intervals. Rats were sacrificed 24 h, 48 h and 72 h after infection in both PYN and CAPE groups. Malondialdehyde (MDA) and nitric oxide (NO) levels were significantly increased in kidneys of PYN groups. The activities of the antioxidant enzymes, catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and xanthine oxidase (XO) were also elevated by E. coli. However, CAPE administration reduced MDA and NO levels, as well as XO activity, although it increased SOD and GSH-Px activities. Histopathological examination showed that CAPE reduced the inflammation grade induced by E. coli. In conclusion, CAPE administrations decrease the oxidative damage occurring in PYN and therefore could be used for medical management of bacterial nephropathy.     

A novel antioxidant agent caffeic acid phenethyl ester prevents long-term mobile phone exposure-induced renal impairment in rat

Caffeic acid phenethyl ester (CAPE), a flavonoid like compound, is one of the major components of honeybee propolis. It has been used in folk medicine for many years in Middle East countries. It was found to be a potent free radical scavenger and antioxidant recently. The aim of this study was to examine long-term applied 900 MHz emitting mobile phone-induced oxidative stress that promotes production of reactive oxygen species (ROS) and, was to investigate the role of CAPE on kidney tissue against the possible electromagnetic radiation (EMR)-induced renal impairment in rats. In particular, the ROS such as superoxide and nitric oxide (NO) may contribute to the pathophysiology of EMR-induced renal impairment. Malondialdehyde (MDA, an index of lipid peroxidation) levels, urinary N-acetyl-β-d-glucosaminidase (NAG, a marker of renal tubular injury) and nitric oxide (NO, an oxidant product) levels were used as markers of oxidative stress-induced renal impairment and the success of CAPE treatment. The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in renal tissue were determined to evaluate the changes of antioxidant status. The rats used in the study were randomly grouped (10 each) as follows: i) Control group (without stress and EMR), ii) Sham-operated rats stayed without exposure to EMR (exposure device off), iii) Rats exposed to 900 MHz EMR (EMR group), and iv) A 900 MHz EMR exposed + CAPE treated group (EMR + CAPE group). In the EMR exposed group, while tissue MDA, NO levels and urinary NAG levels increased (p < 0.0001), the activities of SOD, CAT, and GSH-Px in renal tissue were reduced (p < 0.001). CAPE treatment reversed these effects as well (p < 0.0001, p < 0.001 respectively). In conclusion, the increase in NO and MDA levels of renal tissue, and in urinary NAG with the decrease in renal SOD, CAT, GSH-Px activities demonstrate the role of oxidative mechanisms in 900 MHz mobile phone-induced renal tissue damage, and CAPE, via its free radical scavenging and antioxidant properties, ameliorates oxidative renal damage. These results strongly suggest that CAPE exhibits a protective effect on mobile phone-induced and free radical mediated oxidative renal impairment in rats.     

The spin trap 5,5-dimethyl-1-pyrroline N-oxide inhibits lipopolysaccharide-induced inflammatory response in RAW 264.7 cells

AimExposure of macrophages to lipopolysaccharide (LPS) induces oxidative and inflammatory stresses, which cause cell damage. Antioxidant and anti-inflammatory properties have been attributed to the nitrone spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO), commonly used in free radical analysis, but these aspects of DMPO have been little explored. In this study, we sought to establish the anti-inflammatory activity of DMPO, presumably by removing free radicals which otherwise help activate inflammatory response and damage cells.Main methodsRAW 264.7 macrophages were treated with LPS and/or DMPO for different time points, cell damage, production of inflammatory mediators, inducible nitric oxide synthase (iNOS) expression, NF-κB p65 activation, phosphorylation of MAPKs and Akt, and intracellular reactive oxygen species (ROS) were determined.Key findingsAfter cells were treated with LPS and/or DMPO for 24 h, DMPO reduced the LPS-induced inflammatory response as indicated by downregulated iNOS expression and production of inflammatory mediators. Accordingly, DMPO protected cells from LPS-induced cytotoxicity. In order to understand the mechanistic basis of these DMPO effects, the NF-κB p65 activation and the phosphorylation of MAPKs and Akt were examined. We found, by assaying cells treated with LPS and/or DMPO for 15–60 min, that DMPO inhibited the phosphorylation of MAPKs, Akt, and IκBα, and reduced the NF-κB p65 translocation. Furthermore, we demonstrated that DMPO inhibited LPS-induced ROS production.SignificanceDMPO showed the anti-inflammatory activity and attenuated LPS-induced cell damage, most likely by reducing ROS production and thus preventing the subsequent inflammatory activation and damage.     

Protective effects of peroxiredoxin-1 at the injured blood-brain barrier

Reactive oxygen species (ROS) play a pivotal role in the development of neuroinflammatory disorders, such as multiple sclerosis (MS). Here, we studied the effect of ROS on protein expression in brain endothelial cells (BECs) using proteomic techniques and show that long-term exposure to ROS induces adaptive responses in BECs to counteract an oxidative attack. ROS induce differential protein expression in BECs, among which is peroxiredoxin-1 (Prx1). To further study the role of Prx1 we established a BEC line overexpressing Prx1. Our data indicate that Prx-1 overexpression protects BECs from ROS-induced cell death, reduces adhesion and subsequent transendothelial migration of monocytes by decreasing intercellular adhesion molecule-1 expression, and enhances the integrity of the BEC layer. Interestingly, vascular Prx1 immunoreactivity was markedly upregulated in inflammatory lesions of experimental autoimmune encephalomyelitis (EAE) animals and active demyelinating MS lesions. These findings indicate that enhanced vascular Prx1 expression may reflect the occurrence of vascular oxidative stress in EAE and MS. On the other hand, it may function as an endogenous defense mechanism to inhibit leukocyte infiltration and counteract ROS-induced cellular injury.     

Protein Restriction Without Strong Caloric Restriction Decreases Mitochondrial Oxygen Radical Production and Oxidative DNA Damage in Rat Liver

Previous studies have shown that caloric restriction decreases mitochondrial oxygen radical production and oxidative DNA damage in rat organs, which can be linked to the slowing of aging rate induced by this regime. These two characteristics are also typical of long-lived animals. However, it has never been investigated if those decreases are linked to the decrease in the intake of calories themselves or to decreases in specific dietary components. In this study the possible role of the dietary protein was investigated. Using semipurified diets, the ingestion of proteins of Wistar rats was decreased by 40% below that of controls while the other dietary components were ingested at the same level as in animals fed ad libitum. After seven weeks in this regime the liver of the protein restricted animals showed 30–40% decreases in mitochondrial production of reactive oxygen species (ROS) and in oxidative damage to nuclear and mitochondrial DNA. The decreases in ROS generation occurred specifically at complex~I. They also occurred without changes in mitochondrial oxygen consumption. Instead, there was a decrease in the percent free radical leak (the percentage of total electron flow leading to ROS generation in the respiratory chain). These results are strikingly similar to those previously obtained after 40% caloric restriction in the liver of Wistar rats. Thus, the results suggest that part of the decrease in aging rate induced by caloric restriction can be due to the decreased intake of proteins acting through decreases in mitochondrial ROS production and oxidative DNA damage. Interestingly, these tissue oxidative stress-linked parameters can be lowered by restricting only the intake of dietary protein, probably a more feasible option than caloric restriction for adult humans.     

Green tea epigallocatechin-3-gallate mediates T cellular NF-kappa B inhibition and exerts neuroprotection in autoimmune encephalomyelitis

Recent studies in multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), point to the fact that even in the early phase of inflammation, neuronal pathology plays a pivotal role in the sustained disability of affected individuals. We show that the major green tea constituent, (-)-epigallocatechin-3-gallate (EGCG), dramatically suppresses EAE induced by proteolipid protein 139-151. EGCG reduced clinical severity when given at initiation or after the onset of EAE by both limiting brain inflammation and reducing neuronal damage. In orally treated mice, we found abrogated proliferation and TNF-alpha production of encephalitogenic T cells. In human myelin-specific CD4+ T cells, cell cycle arrest was induced, down-regulating the cyclin-dependent kinase 4. Interference with both T cell growth and effector function was mediated by blockade of the catalytic activities of the 20S/26S proteasome complex, resulting in intracellular accumulation of IkappaB-alpha and subsequent inhibition of NF-kappaB activation. Because its structure implicates additional antioxidative properties, EGCG was capable of protecting against neuronal injury in living brain tissue induced by N-methyl-D-aspartate or TRAIL and of directly blocking the formation of neurotoxic reactive oxygen species in neurons. Thus, a natural green tea constituent may open up a new therapeutic avenue for young disabled adults with inflammatory brain disease by combining, on one hand, anti-inflammatory and, on the other hand, neuroprotective capacities.     

LL202 ameliorates colitis against oxidative stress of macrophage by activation of the Nrf2/HO-1 pathway

LL202, a newly synthesized flavonoid derivative, has been confirmed to inhibit the mitogen-activated protein kinase pathway and activation protein-1 activation in monocytes; however, the anti-inflammatory mechanism has not been clearly studied. Uncontrolled overproduction of reactive oxygen species (ROS) has involved in oxidative damage of inflammatory bowel disease. In this study, we investigated that LL202 reduced lipopolysaccharide (LPS)-induced ROS production and malondialdehyde levels and increased superoxide dismutase, glutathione, and total antioxidant capacity in RAW264.7 cells. Mechanically, LL202 could upregulate heme oxygenase-1 (HO-1) via promoting nuclear translocation of nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) to regulate LPS-induced oxidative stress in macrophages. In vivo, we validated the role of LL202 in dextran sulfate sodium- and TNBS-induced colitis models, respectively. The results showed that LL202 decreased the proinflammatory cytokine expression and regulated colonic oxidative stress by activating the Nrf2/HO-1 pathway. In conclusion, our study showed that LL202 exerts an anti-inflammatory effect by enhancing the antioxidant capacity of the Nrf2/HO-1 pathway to macrophages.     

The oxidation state of phospholipids controls the oxidative burst in neutrophil granulocytes

The activation of neutrophil granulocytes has to be carefully controlled to balance desired activity against invading pathogens while avoiding overwhelming activation leading to host tissue damage. We now show that phospholipids are potential key players in this process by either enhancing or dampening the production of reactive oxygen species (ROS) during the oxidative burst. Unoxidized phospholipids induce the production of ROS, and they also work synergistically with FMLP in potentiating the oxidative burst in neutrophil granulocytes. Oxidation of these phospholipids, however, turns them into potent inhibitors of the oxidative burst. OxPls specifically inhibit ROS production by inhibiting the assembly of the phagocyte oxidase complex but do not alter neutrophil viability, nor do they interfere with MAPK activation. Furthermore, up-regulation of the activation marker Mac-1 and phagocytosis of bacteria is not affected. Therefore, phospholipids may act as sensors of oxidative stress in tissues and either positively or negatively regulate neutrophil ROS production according to their oxidation state.     

Role of redox imbalance and cytokines in mediating oxidative damage and disease progression of patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune disorder wherein the contributory role of oxidative stress has been established in the synovial fluid. As availability of synovial fluid is limited, this study aimed to evaluate in the peripheral blood of patients with RA, the relationship if any, between the extent of oxidative stress in terms of generation of reactive oxygen species (ROS) in neutrophils, plasma NADPH oxidase and myeloperoxidase activity with markers of oxidative damage, circulating cytokines and disease activity score (DAS28). In patients with RA, neutrophils in peripheral blood demonstrated an enhanced generation of ROS, coupled with depletion of free radical scavenging activity. Furthermore, the NADPH oxidase and myeloperoxidase activity was enhanced as were markers of damage. There was a positive correlation between the DAS 28 and generation of ROS, NADPH oxidase and myeloperoxidase activity as also with oxidative stress mediated protein carbonylation. Patients with RA demonstrated an increase in proinflammatory (IL-17, IL-23, and IFN-γ) and some anti-inflammatory (IL-4, IL-5, and TGF-β) cytokines. Although the levels of IL-17 correlated positively with generation of ROS, myeloperoxidase, markers of protein damage and DAS28, IL-23 correlated positively only with protein damage, and negatively with free radical scavenging activity. Importantly, incubation of neutrophils from healthy donors with plasma or SF from patients with RA translated into an enhanced generation of ROS, along with an elevation of intracellular proinflammatory cytokines. Taken together, in patients with RA, circulating neutrophils mediated a shift in the oxidant/antioxidant balance favouring the former, which translated into protein damage and contributed towards disease progression.     

Caffeic acid phenethyl ester attenuates allergic airway inflammation and hyperresponsiveness in murine model of ovalbumin-induced asthma

Caffeic acid phenethyl ester (CAPE) is a biologically active ingredient of propolis, which has several interesting biological properties, including antioxidant and anti-inflammatory; however, its anti-allergic effects are poorly understood. The objective of this study was to determine whether treatment with CAPE results in significant inhibition of asthmatic reactions in a mouse model. Mice sensitized and challenged with ovalbumin (OVA) had the following typical asthmatic reactions: an increase in the number of eosinophils in bronchoalveolar lavage (BAL) fluid; a marked influx of inflammatory cells into the lung around blood vessels and airways, and airway luminal narrowing; the development of airway hyperresponsiveness (AHR); the presence of tumor necrosis factor-alpha (TNF-alpha) and Th2 cytokines, including IL-4 and IL-5, in the BAL fluid; and the presence of allergen-specific IgE in the serum. Five successive intraperitoneal administrations of CAPE before the last airway OVA challenge resulted in significant inhibition of characteristic asthmatic reactions. We determined that increased generation of reactive oxygen species (ROS) by inhalation of OVA was diminished via the administration of CAPE in BAL fluid, as well as nuclear factor-kappaB (NF-kappaB) DNA binding activity. These findings indicate that oxidative stress may have a crucial function in the pathogenesis of bronchial asthma, and that CAPE may be useful as an adjuvant therapy for the treatment of bronchial asthma.     

Levels of oxidative damage and proinflammatory cytokines are enhanced in patients with active vitiligo

Vitiligo is an autoimmune depigmenting skin disease characterised by loss of melanocytes wherein oxidative stress is proposed to be the initial triggering factor with subsequent immune dysregulation. This study aimed to evaluate the relationship, if any, between the generation of reactive oxygen species (ROS), markers of oxidative damage and circulating cytokines in patients with active vitiligo. The generation of ROS in erythrocytes and neutrophils was significantly higher in patients with active vitiligo than healthy controls. Alongside, markers of oxidative stress-mediated damage namely lipid peroxidation, DNA damage and protein carbonylation were evaluated. Patients with active vitiligo demonstrated increased lipid and DNA damage but minimal protein damage. There was a significant decline in the free radical scavenging capacity of active vitiligo cases. A positive correlation existed between baseline levels of ROS and lipid peroxidation as also DNA damage. Patients with active vitiligo demonstrated an increase in several proinflammatory (IL-6, TNF-α, IL-1β, IFN-γ and IL-8) and some anti-inflammatory/immunoregulatory (IL-5 and IL-10) cytokines. Importantly, the levels of IFN-γ and IL-10 consistently correlated with the generation of ROS, markers of damage and their free radical scavenging capacity. Taken together, patients with active vitiligo demonstrated an enhanced generation of ROS in erythrocytes and neutrophils which mediated lipid peroxidation, DNA damage and coupled with a decline in their antioxidant capacity created a pro-oxidant milieu that favoured tissue damage and potential generation of neoantigens, accounting for disease progression.     

Aminoguanidine and N-acetyl-cysteine supress oxidative and nitrosative stress in EAE rat brains

Experimental autoimmune encephalomyelitis (EAE) is a well-established animal model of human multiple sclerosis (MS). We have evaluated the role of oxidative and nitrosative stress, as the causal factors in the development of EAE, responsible for the damage of cardinal cellular components, such as lipids, proteins and nucleic acids, resulting in demyelination, axonal damage, and neuronal death. EAE was induced in female Sprague-Dawley rats, 3 months old (300±20 g), by immunization with myelin basic protein in combination with Complete Freund's adjuvant (CFA). The animals were divided into seven groups: control, EAE, CFA, EAE+aminoguanidine (AG), AG, EAE+N-acetyl-L-cysteine (NAC) and NAC. The animals were sacrificed 15 days after EAE induction, and the levels of nitrosative and oxidative stress were determined in 10% homogenate of the whole encephalitic mass. In EAE rats, brain NO production and MDA level were significantly increased (P<0.001) compared to the control values, whereas AG and NAC treatment decreased both parameters in EAE rats compared to EAE group (P<0.001). Glutathione (GSH) was reduced (P<0.001) in EAE rats in comparison with the control and CFA groups, but increased in EAE+AG and EAE+NAC group compared to the EAE group (P<0.01). Superoxide dismutase (SOD) activity was significantly decreased (P<0.001) in the EAE group compared to all other experimental groups. The clinical expression of EAE was significantly decreased (P<0.05) in the EAE groups treated with AG and NAC compared to EAE rats, during disease development. The obtained results prove an important role of oxidative and nitrosative stress in the pathogenesis of EAE, whereas AG and NAC protective effects offer new possibilities for a modified combined approach in MS therapy.     

Increased Reactive Oxygen Species Formation and Oxidative Stress in Rheumatoid Arthritis

BackgroundRheumatoid arthritis (RA) is an autoimmune inflammatory disorder. Highly reactive oxygen free radicals are believed to be involved in the pathogenesis of the disease. In this study, RA patients were sub-grouped depending upon the presence or absence of rheumatoid factor, disease activity score and disease duration. RA Patients (120) and healthy controls (53) were evaluated for the oxidant—antioxidant status by monitoring ROS production, biomarkers of lipid peroxidation, protein oxidation and DNA damage. The level of various enzymatic and non-enzymatic antioxidants was also monitored. Correlation analysis was also performed for analysing the association between ROS and various other parameters.MethodsIntracellular ROS formation, lipid peroxidation (MDA level), protein oxidation (carbonyl level and thiol level) and DNA damage were detected in the blood of RA patients. Antioxidant status was evaluated by FRAP assay, DPPH reduction assay and enzymatic (SOD, catalase, GST, GR) and non-enzymatic (vitamin C and GSH) antioxidants.ResultsRA patients showed a higher ROS production, increased lipid peroxidation, protein oxidation and DNA damage. A significant decline in the ferric reducing ability, DPPH radical quenching ability and the levels of antioxidants has also been observed. Significant correlation has been found between ROS and various other parameters studied.ConclusionRA patients showed a marked increase in ROS formation, lipid peroxidation, protein oxidation, DNA damage and decrease in the activity of antioxidant defence system leading to oxidative stress which may contribute to tissue damage and hence to the chronicity of the disease.     

The long life of birds: the rat-pigeon comparison revisited

The most studied comparison of aging and maximum lifespan potential (MLSP) among endotherms involves the 7-fold longevity difference between rats (MLSP 5y) and pigeons (MLSP 35y). A widely accepted theory explaining MLSP differences between species is the oxidative stress theory, which purports that reactive oxygen species (ROS) produced during mitochondrial respiration damage bio-molecules and eventually lead to the breakdown of regulatory systems and consequent death. Previous rat-pigeon studies compared only aspects of the oxidative stress theory and most concluded that the lower mitochondrial superoxide production of pigeons compared to rats was responsible for their much greater longevity. This conclusion is based mainly on data from one tissue (the heart) using one mitochondrial substrate (succinate). Studies on heart mitochondria using pyruvate as a mitochondrial substrate gave contradictory results. We believe the conclusion that birds produce less mitochondrial superoxide than mammals is unwarranted. We have revisited the rat-pigeon comparison in the most comprehensive manner to date. We have measured superoxide production (by heart, skeletal muscle and liver mitochondria), five different antioxidants in plasma, three tissues and mitochondria, membrane fatty acid composition (in seven tissues and three mitochondria), and biomarkers of oxidative damage. The only substantial and consistent difference that we have observed between rats and pigeons is their membrane fatty acid composition, with rats having membranes that are more susceptible to damage. This suggests that, although there was no difference in superoxide production, there is likely a much greater production of lipid-based ROS in the rat. We conclude that the differences in superoxide production reported previously were due to the arbitrary selection of heart muscle to source mitochondria and the provision of succinate. Had mitochondria been harvested from other tissues or other relevant mitochondrial metabolic substrates been used, then very different conclusions regarding differences in oxidative stress would have been reached.     

Oxidative stress as a potential biomarker for determining disease activity in patients with Rheumatoid Arthritis

Rheumatoid arthritis is an inflammatory, autoimmune disease where oxidative stress has been proposed to contribute to the joint tissue damage. To establish whether measurement of the redox status in blood mirrors the oxidant status at sites of inflammation in patients with rheumatoid arthritis, we concomitantly examined their oxidant status by spectrophotometry and/or flow cytometry. The basal levels of total reactive oxygen species (ROS), superoxide and hydroxyl radicals were significantly raised in neutrophils sourced from peripheral blood and synovial infiltrate, as also showed a strong positive correlation; however, there was no major increase in the reactive nitrogen species RNS generated in monocytes from both sources. Furthermore, raised levels of superoxide in neutrophils of synovial infiltrate showed a positive correlation with NADPH oxidase activity in synovial fluid. Additionally, as ROS generated in both peripheral blood and synovial infiltrate correlated positively with both DAS 28 and CRP/anti-CCP levels, its measurement can serve as an indirect measure of the degree of inflammation in patients with RA.     

Total synthesis and biological evaluation of viscolin, a 1,3-diphenylpropane as a novel potent anti-inflammatory agent

Total synthesis of viscolin, an anti-inflammatory 1,3-diphenylpropane isolated from Viscum coloratum, employing the Wittig reaction is reported. Key steps in the synthesis of viscolin depend on the selection of protecting groups to maintain the para hydroxyl group that is the most critical chemical structure influencing the biological activity of viscolin and the utilization of microwave-assisted Wittig olefination reaction. Anti-inflammatory potency of the synthetic viscolin, its precursor product 16, and its analogue 17, through their effects on reactive oxygen species (ROS), nitric oxide (NO), and pro-inflammatory cytokine production in leukocytes and microglial cells were evaluated. Excellent inhibition of ROS and NO production in inflammatory cells could confer the synthetic viscolin to be a potent anti-inflammatory agent for the treatment of oxidative stress-induced diseases.     

Pathogenic and protective functions of TNF in neuroinflammation are defined by its expression in T lymphocytes and myeloid cells

TNF displays pathogenic activities in many autoimmune disorders. However, anti-TNF therapy in multiple sclerosis patients failed because of poorly understood reasons. We used a panel of gene-targeted mice that allowed cell-type specific ablation of TNF to uncover pathogenic and protective contributions of this cytokine during autoimmune disease of the CNS. T cells and myeloid cells were found to be critical cellular sources of TNF during experimental autoimmune encephalomyelitis (EAE). TNF produced by myeloid cells accelerated the onset of disease by regulation of chemokine expression in the CNS, driving the recruitment of inflammatory cells into the target organ. TNF produced by T cells exacerbated the damage to the CNS during EAE by regulating infiltration of inflammatory myeloid cells into the CNS. In secondary lymphoid organs, TNF expressed by myeloid cells and T cells acted in synergy to dampen IL-12p40 and IL-6 production by APCs, subsequently inhibiting the development of encephalitogenic T cell responses of Th1 and Th17 types. This dual role of TNF during EAE (protective in lymphoid organs and pathogenic in CNS) suggests that global TNF blockade might be inefficient in multiple sclerosis patients because augmented autoreactive T cell development in lymphoid tissues might overwhelm the beneficial effects resulting from TNF inhibition in the CNS.     

Kidney cell death in inflammation: The role of oxidative stress and mitochondria

Pyelonephritis is an infectious disease, and common treatment strategy is based on antibiotic therapy directed at the elimination of a pathogen. However, urinary tract infections are accompanied by inflammation and oxidative stress, which are major damaging factors, and therefore can serve as a target for therapeutic intervention. The goal of this study was to clarify the role of the mitochondrial reactive oxygen species (ROS) in kidney cell damage under experimental pyelonephritis. We investigated the mechanisms of inflammation and the role of mitochondria and oxidative stress in inflammation in kidney tissue using in vivo and in vitro models of pyelonephritis. We observed the development of oxidative stress in renal tubular epithelium in vitro, and resulting apoptotic cell death. This oxidative damage was caused by the leukocytes producing ROS after interaction with bacterial antigens. The essential role of mitochondria-mediated oxidative stress was confirmed using an experimental model of pyelonephritis in vivo. We revealed increased levels of malonic dialdehyde in kidneys of rats with experimental pyelonephritis that pointed to lipid peroxidation. Besides, high ROS levels were observed in blood leukocytes from rats with pyelonephritis. The mitochondria-targeted antioxidant SkQ1 significantly reduced the signs of kidney inflammatory injury, in particular the infiltration of neutrophils. Summarizing the data obtained, we assume the importance of mitochondrial ROS in different phases of acute pyelonephritis onset. Protection of kidney cells from infection-mediated damage can be attained by the induction of tolerance mechanisms and by antioxidant treatment.     

Targeting the Shift from M1 to M2 Macrophages in Experimental Autoimmune Encephalomyelitis Mice Treated with Fasudil

We observed the therapeutic effect of Fasudil and explored its mechanisms in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Fasudil, a selective Rho kinase (ROCK) inhibitor, was injected intraperitoneally at 40 mg/kg/d in early and late stages of EAE induction. Fasudil ameliorated the clinical severity of EAE at different stages, and decreased the expression of ROCK-II in spleen, accompanied by an improvement in demyelination and inhibition of inflammatory cells. Fasudil mainly inhibited CD4⁺IL-17⁺ T cells in early treatment, but also elevated CD4⁺IL-10⁺ regulatory T cells and IL-10 production in late treatment. The treatment of Fasudil shifted inflammatory M1 to anti-inflammatory M2 macrophages in both early and late treatment, being shown by inhibiting CD16/32, iNOS, IL-12, TLR4 and CD40 and increasing CD206, Arg-1, IL-10 and CD14 in spleen. By using Western blot and immunohistochemistry, iNOS and Arg-1, as two most specific markers for M1 and M2, was inhibited or induced in splenic macrophages and spinal cords of EAE mice treated with Fasudil. In vitro experiments also indicate that Fasudil shifts M1 to M2 phenotype, which does not require the participation or auxiliary of other cells. The polarization of M2 macrophages was associated with the decrease of inflammatory cytokine IL-1β, TNF-α and MCP-1. These results demonstrate that Fasudil has therapeutic potential in EAE possibly through inducing the polarization of M2 macrophages and inhibiting inflammatory responses.