PD1/PD-L1 immune checkpoint as a potential target for preventing brain tumor progression.

Programmed death-1 (PD-1) is a cell surface receptor that functions as a T cell checkpoint and plays a central role in regulating T cell collapse. The binding of PD-1 to its ligand programmed death-ligand 1 (PD-L1) activates downstream signaling pathways and inhibits T cell activation in the perspective of immune system mechanism and regulation in tumor progression. It is well reported that tumors adopt certain immune-checkpoint pathways as a mechanism of resistance against immune cells such as T cells that are specific for tumor antigens. Indeed, the PD-1/PD-L1 pathway controls the induction and maintenance of immune tolerance within the tumor microenvironment. Thus, the PD-1/PD-L1 checkpoint regulation appears to be of extreme importance as well as the immunotherapy targeting that via and the using of PD-1/PD-L1 inhibitors that have changed the scenario of brain cancer treatment and survival. Here, we review the mechanism of action of PD-1 and PD-L1, the PD/PDL-1 signaling pathway involved in the progression of brain tumors, and its application as cancer immunotherapy counteracting tumor escape in central nervous system.

Protective effect of sodium propionate in Aß1-42 -induced neurotoxicity and spinal cord trauma.

Sodium propionate (SP) is one of the main short chain fatty acids (SCFA) that can be produced naturally through host metabolic pathways. SP have been documented and include the reduction of pro-inflammatory mediators in an in vivo model of colitis. The aim of this study is to evaluate the neuroprotective effects of SP in reducing inflammatory process associated to neurological disorders. We performed both in vitro model of Alzheimer's disease, induced by oligomeric Aß1-42 stimulation, and in in vivo model of spinal cord injury (SCI) in which neuroinflammation plays a crucial role. For in vitro model, the human neuroblastoma SH-SY5Y cell line was first differentiated with retinoic acid (100 µM) for 24 h and then stimulated by oligomeric Aß1-42 (1 µg/ml) and treated with SP at 0.1- 1-10 µM concentrations for another 24 h. Instead, the in vivo model of SCI was induced by extradural compression of the spinal cord at T6-T8 levels, and animals were treated with SP (10-30-100 mg/kg o.s) 1 and 6 h after SCI. Our results demonstrated that both in in vitro neuroinflammatory model and in vivo model of SCI the treatment with SP significantly reduced NF-κB nuclear translocation and IκBα degradation, as well as decreases COX-2 and iNOS expressions evaluated by Western blot analysis. Moreover, we showed that SP treatment significantly ameliorated histopathology changes and improved motor recovery in a dose-dependent manner. In conclusion, our results demonstrated that SP possesses neuroprotective effects, suggesting it could represent a target for therapeutic intervention in neuroinflammatory disorders.

Sodium Butyrate Exerts Neuroprotective Effects in Spinal Cord Injury.

Sodium butyrate (SB) is a dietary microbial fermentation product and serves as an important neuromodulator in the central nervous system. Recent experimental evidence has suggested potential therapeutic applications for butyrate, including its utility in treating metabolic and inflammatory diseases. The aim of the present study was to evaluate the potential beneficial effects of SB in a mouse model of spinal cord injury (SCI) and its possible mechanism of action. SCI was induced by extradural compression for 1 min of the spinal cord at the T6-7 level using an aneurysm clip, and SB (10-30-100 mg/kg) was administered by oral gavage 1 and 6 h after SCI. For locomotor activity, study mice were treated with SB once daily for 10 days. Morphological examination was performed by light microscopy through hematoxylin-eosin (H&E) staining. In addition, NF-κB, IκB-α, COX-2, and iNOS expressions were assayed by western blot analysis and IL-1ß and TNF-α levels by immunohistochemistry analysis. The results showed that SB treatment significantly ameliorated histopathology changes and improved recovery of motor function changes in spinal cord injury in a dose-dependent manner. Moreover, we demonstrated that SB modulated the NF-κB pathway showing a significant reduction in cytokine expression. Thus, this study showed that SB exerts neuroprotective effects anti-inflammatory properties following spinal cord injury suggesting that SB may serve as a potential candidate for future treatment of spinal cord injury.

PPAR-α Modulates the Anti-Inflammatory Effect of Melatonin in the Secondary Events of Spinal Cord Injury.

Melatonin is the principal secretory product of the pineal gland, and its role as an immunomodulator is well established. Recent evidence shows that melatonin is a scavenger of oxyradicals and peroxynitrite and reduces the development of inflammation and tissue injury events associated with spinal cord trauma. Previous results suggest that peroxisome proliferator-activated receptor α (PPAR-α), a nuclear receptor protein that functions as a transcription factor activated by fatty acids, plays a role in control of secondary inflammatory process associated with spinal cord injury (SCI).With the aim to characterize the role of PPAR-α in melatonin-mediated anti-inflammatory activity, we tested the efficacy of melatonin (30 mg/kg) in an experimental model of spinal cord trauma, induced in mice, by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy, and comparing mice lacking PPAR-α (PPAR-α KO) with wild-type (WT) mice.The results obtained indicate that melatonin-mediated anti-inflammatory activity is weakened in PPAR-α KO mice, as compared to WT controls. In particular, melatonin was less effective in PPAR-α KO, compared to WT mice, as evaluated by inhibition of the degree of spinal cord inflammation and tissue injury, neutrophil infiltration, pro-inflammatory cytokine expression, nuclear factor κB (NF-κB) activation, and inducible nitric oxide synthase (iNOS) expression. This study indicates that PPAR-α can contribute to the anti-inflammatory activity of melatonin in SCI.

Redox modulation of cellular stress response and lipoxin A4 expression by Hericium Erinaceus in rat brain: relevance to Alzheimer's disease pathogenesis.

BACKGROUND: There has been a recent upsurge of interest in complementary medicine, especially dietary supplements and foods functional in delaying the onset of age-associated neurodegenerative diseases. Mushrooms have long been used in traditional medicine for thousands of years, being now increasingly recognized as antitumor, antioxidant, antiviral, antibacterial and hepatoprotective agent also capable to stimulate host immune responses. RESULTS: Here we provide evidence of neuroprotective action of Hericium Herinaceus when administered orally to rat. Expression of Lipoxin A4 (LXA4) was measured in different brain regions after oral administration of a biomass Hericium preparation, given for 3 month. LXA4 up-regulation was associated with an increased content of redox sensitive proteins involved in cellular stress response, such as Hsp72, Heme oxygenase -1 and Thioredoxin. In the brain of rats receiving Hericium, maximum induction of LXA4 was observed in cortex, and hippocampus followed by substantia Nigra, striatum and cerebellum. Increasing evidence supports the notion that oxidative stress-driven neuroinflammation is a fundamental cause in neurodegenerative diseases. As prominent intracellular redox system involved in neuroprotection, the vitagene system is emerging as a neurohormetic potential target for novel cytoprotective interventions. Vitagenes encode for cytoprotective heat shock proteins 70, heme oxygenase-1, thioredoxin and Lipoxin A4. Emerging interest is now focussing on molecules capable of activating the vitagene system as novel therapeutic target to minimize deleterious consequences associated with free radical-induced cell damage, such as in neurodegeneration. LXA4 is an emerging endogenous eicosanoid able to promote resolution of inflammation, acting as an endogenous "braking signal" in the inflammatory process. In addition, Hsp system is emerging as key pathway for modulation to prevent neuronal dysfunction, caused by protein misfolding. CONCLUSIONS: Conceivably, activation of LXA4 signaling and modulation of stress responsive vitagene proteins could serve as a potential therapeutic target for AD-related inflammation and neurodegenerative damage.

Thyroid hormone autoantibodies: are they a better marker to detect early thyroid damage in patients with hematologic cancers receiving tyrosine kinase inhibitor or immunoregulatory drug treatments?

BACKGROUND: Unlike cytotoxic agents, novel antineoplastic drugs can variably affect thyroid function and so impair patient outcomes. However, the widely used standard thyroid tests have demonstrated low sensitivity for detecting early thyroid damage that leads to dysfunction of the gland. To find a more reliable thyroid marker, we assessed the presence of antibodies binding thyroid hormones (thAbs) in a cancer population undergoing potentially thyrotoxic treatment. METHODS: From April 2010 to September 2013, 82 patients with hematologic malignancies treated with tyrosine kinase inhibitors or immunoregulatory drugs were recruited. Healthy volunteers (n = 104) served as control subjects. Thyroid function, autoimmunity tests, thAbs, and thyroid sonography were assessed once during treatment. RESULTS: Overall, thAb positivity was recorded in 13% of the entire cohort. In most cases, the thAbs were of a single type, with a predominance of T3 immunoglobulin G. More specifically, thAbs were detected in 11 cancer patients; and abnormal levels of thyroid-stimulating hormone, thyroglobulin antibody, and thyroperoxidase antibody were detected in 6 (p = 0.05), 0 (p = 0.0006), and 2 cancer patients (p = 0.001) respectively. Ultrasonographic alterations of the thyroid were observed in 12 cancer patients. In contrast, of the 104 healthy control subjects, only 1 was positive for thAbs (1%). CONCLUSIONS: We have demonstrated for the first time that thAbs are a reliable marker of early thyroid dysfunction when compared with the widely used standard thyroid tests. A confirmatory prospective trial aiming at evaluating thAbs at various time points during treatment could clarify the incidence and timing of antibody appearance.

A new co-micronized composite containing palmitoylethanolamide and polydatin shows superior oral efficacy compared to their association in a rat paw model of carrageenan-induced inflammation.

Palmitoylethanolamide (PEA), a special food for medical purposes, has anti-inflammatory and neuroprotective effects. Nevertheless, PEA lacks direct ability to prevent free radical formation. Polydatin (PLD), a natural precursor of resveratrol, has antioxidant activity. The combination of PEA and PLD could have beneficial effects on oxidative stress induced by inflammatory processes. In the present study, we compared the effects of micronized PEA (PEA-m) and PLD association (PEA-m+PLD) with a new co-micronized composite containing PEA and PLD (m(PEA/PLD)) in the rat paw model of carrageenan (CAR)-induced acute inflammation. Intraplantar injection of CAR led to a time-dependent development of peripheral inflammation, in terms of paw edema, cytokine release in paw exudates, nitrotyrosine formation, inducible nitric oxide synthase and cyclooxygenase-2 expression. m(PEA/PLD) reduced all measured parameters. Thermal hyperalgesia and mechanical allodynia were also markedly reduced. At the spinal cord level, manganese superoxide dismutase (MnSOD) was found to be nitrated and subsequently deactivated. Further, m(PEA/PLD) treatment increased spinal MnSOD expression, prevented IkB-α degradation and nuclear factor-κB translocation, suggesting a possible role on central sensitization. m(PEA/PLD) showed more robust anti-inflammatory and anti-hyperalgesic effects compared to the simple association of PEA-m and PLD. This composite formulation approach opens a new therapeutic strategy for the development of novel non-narcotic anti-hyperalgesic agents.

A novel protective formulation of Palmitoylethanolamide in experimental model of contrast agent induced nephropathy.

Contrast-induced nephropathy (CIN) is a complication in patients after administration of iodinated contrast media. Several risk factors contribute to the development and progression of CIN, including hypertension, diabetes, and dyslipidemia. Animal models of CIN by surgical intervention to reproduce its clinical and pathology has been developed, and thus, therapeutic methods tested. Palmitoylethanolamide (PEA) is a member of the fatty acid ethanolamine family with analgesic and anti-inflammatory effects. In this study, we analyzed streptozotocin-induced diabetes model and in an another set of experiment a surgical remotion of the kidney with the aim of evaluating effect of ultramicronized Palmitoylethanolamide (PEA-um(®)) on contrast induced renal disfunction and glomerular morphology alteration. In a first step of our study, we demonstrated that PEA-um(®) significantly reduced CIN-mediated glomerular dysfunction, modulates Na(+) and K(+) levels in plasma and decreased urine and plasma NGAL levels and α-GST urine levels. Moreover, in a second set of experiment we investigated how PEA-um(®) reduced creatinine and BUN plasma levels after nephrectomy, ameliorate renal and medullary blood flow and re-established renal parenchymal after CIN induction as well as after nephrectomy. Take together our results demonstrated that PEA-um(®) are able to preventing CIN in diabetic rats and alteration of biochemical parameters after nephrectomy.

Redox modulation of cellular stress response and lipoxin A4 expression by Coriolus versicolor in rat brain: Relevance to Alzheimer's disease pathogenesis.

Increasing evidence supports the notion that oxidative stress-driven neuroinflammation is an early pathological feature in neurodegenerative diseases. As a prominent intracellular redox system involved in neuroprotection, the vitagene system is emerging as a potential neurohormetic target for novel cytoprotective interventions. Vitagenes encode for cytoprotective heat shock proteins 70, heme oxygenase-1, thioredoxin and lipoxin A4. Emerging interest is now focusing on molecules capable of activating the vitagene system as novel therapeutic targets to minimize deleterious consequences associated with free radical-induced cell damage, such as in neurodegeneration. Mushroom-derived lipoxin A4 (LXA4) is an emerging endogenous eicosanoid able to promote resolution of inflammation, acting as an endogenous "braking signal" in the inflammatory process. Mushrooms have long been used in traditional medicine for thousands of years, being now increasingly recognized as rich source of polysaccharopeptides endowed with significant antitumor, antioxidant, antiviral, antibacterial and cytoprotective effects, thereby capable of stimulating host immune responses. Here we provide evidence of a neuroprotective action of the Coriolus mushroom when administered orally to rat. Expression of LXA4 was measured in different brain regions after oral administration of a Coriolus biomass preparation, given for 30 days. LXA4 up-regulation was associated with an increased content of redox sensitive proteins involved in cellular stress response, such as Hsp72, heme oxygenase-1 and thioredoxin. In the brain of rats receiving Coriolus, maximum induction of LXA4 was observed in cortex and hippocampus. Hsps induction was associated with no significant changes in IkBα, NFkB and COX-2 brain levels. Conceivably, activation of LXA4 signaling and modulation of stress-responsive vitagene proteins could serve as a potential therapeutic target for AD-related inflammation and neurodegenerative damage.

NADPH-oxidase 2 activation promotes opioid-induced antinociceptive tolerance in mice.

The analgesic effectiveness of long-term opioid therapies is compromised by the development of antinociceptive tolerance linked to the overt production of peroxynitrite (ONOO(-), PN), the product of the interaction between superoxide (O2(-), SO) and nitric oxide (NO), and to neuroinflammatory processes. We have recently reported that in addition to post-translational nitration and inactivation of mitochondrial manganese superoxide dismutase (MnSOD), activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase holoenzyme (NOX) in the spinal cord is a major source for the overt production of superoxide-derived PN during the development of morphine-induced antinociceptive tolerance. However, the NOX complex involved in these processes is not known. The objective of these studies is to identify a potential role for the NOX2 complex, an enzyme involved in inflammation. Mice lacking the catalytic subunit of NOX2 (Nox2(-/-)) or its regulatory subunit, p47(phox) (p47(phox)(-/-)), developed antinociceptive tolerance similar to wildtype (wt) mice after 3 days of continuous morphine. However, while wt mice continue to develop tolerance by day six, morphine analgesia was restored in both Nox2(-/-) and p47(phox)(-/-) mice. Moreover, the loss of Nox2 or p47 did not affect acute morphine analgesia in naïve mice. In wt mice, antinociceptive tolerance was associated with increased activation of NOX, nitration of MnSOD, and proinflammatory cytokines production in the spinal cord. These events were markedly attenuated in Nox2(-/-) and p47(phox)(-/-) mice and instead, there was enhanced formation of antiinflammatory cytokine (IL4 and IL10) production. These results suggest that NOX2 activity provides a significant source of superoxide-derived PN to undertake post-translational modifications of mitochondrial MnSOD and to engage neuroinflammatory signaling in the spinal cord associated with opioid-induced antinociceptive tolerance. Thus, NOX2 may provide a potential target for adjuvant therapy to protect opioid analgesia.

The glucocorticoid-induced TNF receptor family-related protein (GITR) is critical to the development of acute pancreatitis in mice.

BACKGROUND AND PURPOSE: Pancreatitis represents a life-threatening inflammatory condition where leucocytes, cytokines and vascular endothelium contribute to the development of the inflammatory disease. The glucocorticoid-induced tumour necrosis factor (TNF) receptor family-related protein (GITR) is a costimulatory molecule for T lymphocytes, modulates innate and adaptive immune system and has been found to participate in a variety of immune responses and inflammatory processes. Our purpose was to verify whether inhibition of GITR triggering results in a better outcome in experimental pancreatitis. EXPERIMENTAL APPROACH: In male GITR knock-out (GITR(-/-)) and GITR(+/+) mice on Sv129 background, acute pancreatitis was induced after i.p. administration of cerulein. Other experimental groups of GITR(+/+) mice were also treated with different doses of Fc-GITR fusion protein (up to 6.25 µg·mouse⁻¹), given by implanted mini-osmotic pump. Clinical score and pro-inflammatory parameters were evaluated. KEY RESULTS: A less acute pancreatitis was found in GITR(-/-) mice than in GITR(+/+) mice, with marked differences in oedema, neutrophil infiltration, pancreatic dysfunction and injury. Co-treatment of GITR(+/+) mice with cerulein and Fc-GITR fusion protein (6.25 µg·mouse⁻¹) decreased the inflammatory response and tissue injury, compared with treatment with cerulein alone. Inhibition of GITR triggering was found to modulate activation of nuclear factor κB as well as the production of TNF-α, interleukin-1ß, inducible nitric oxide synthase, nitrotyrosine, poly-ADP-ribose, intercellular adhesion molecule-1 and P-selectin. CONCLUSIONS AND IMPLICATIONS: The GITR-GITR ligand system is crucial to the development of acute pancreatitis in mice. Our results also suggest that the Fc-GITR fusion protein could be useful in the treatment of acute pancreatitis.

The 5-lipoxygenase inhibitor, zileuton, suppresses prostaglandin biosynthesis by inhibition of arachidonic acid release in macrophages.

BACKGROUND AND PURPOSE: Zileuton is the only 5-lipoxygenase (5-LOX) inhibitor marketed as a treatment for asthma, and is often utilized as a selective tool to evaluate the role of 5-LOX and leukotrienes. The aim of this study was to investigate the effect of zileuton on prostaglandin (PG) production in vitro and in vivo. EXPERIMENTAL APPROACH: Peritoneal macrophages activated with lipopolysaccharide (LPS)/interferon γ (LPS/IFNγ), J774 macrophages and human whole blood stimulated with LPS were used as in vitro models and rat carrageenan-induced pleurisy as an in vivo model. KEY RESULTS: Zileuton suppressed PG biosynthesis by interference with arachidonic acid (AA) release in macrophages. We found that zileuton significantly reduced PGE2 and 6-keto prostaglandin F1α (PGF1α) levels in activated mouse peritoneal macrophages and in J774 macrophages. This effect was not related to 5-LOX inhibition, because it was also observed in macrophages from 5-LOX knockout mice. Notably, zileuton inhibited PGE2 production in LPS-stimulated human whole blood and suppressed PGE2 and 6-keto PGF1α pleural levels in rat carrageenan-induced pleurisy. Interestingly, zileuton failed to inhibit the activity of microsomal PGE2 synthase1 and of cyclooxygenase (COX)-2 and did not affect COX-2 expression. However, zileuton significantly decreased AA release in macrophages accompanied by inhibition of phospholipase A2 translocation to cellular membranes. CONCLUSIONS AND IMPLICATION: Zileuton inhibited PG production by interfering at the level of AA release. Its mechanism of action, as well as its use as a pharmacological tool, in experimental models of inflammation should be reassessed.

Selective adenosine A(2a) receptor agonists reduce the apoptosis in an experimental model of spinal cord trauma.

Adenosine is an important regulator of inflammatory mechanisms. Functional studies indicate a protective effect of adenosine A2A receptor agonists in spinal cord injury (SCI). The basic molecular mechanisms accounting for their protective effects from spinal cord injury have to be fully elucidated. The aim of this study is to evaluate in vivo protection by two selective A2A receptor agonists, 2-[p-(2-carboxyethyl)phenylethylamino]-50-ethylcarboxamidoadenosine (CGS 21680, 100 microg/kg) and (4-[3-(6-amino-9-(5-cyclopropylcarbamoyl-3,4-dihydroxytetrahydro-furan-2-yl)-9H-purin-2-yl)prop-2-ynyl] piperidine-1-carboxylic acid methyl ester) (ATL 313, 3 microg/kg) on the degree of apoptosis, in the experimental model of spinal cord injury. Spinal cord trauma was induced by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy. Spinal cord trauma in mice was characterised by edema, neutrophilic infiltration and apoptosis. ATL 313, administered by subcutaneously implanted osmotic minipumps after SCI, clearly reduced motor deficit for up to 19 days after operation. The selective A2A receptor agonists ATL 313 and CGS 21680 administered after SCI, reduced tissue damage, TUNEL staining, cytokine (TNF-alpha) expression, Bax, Fas-L and Caspase-3 expression, Annexin-V staining, while increasing Bcl-2 expression. In conclusion, our results demonstrate that treatment with adenosine A2A receptor agonists prevents the apoptotic process that is an important step of secondary damage after SCI.

Heterogeneous expression of cyclooxygenase-2 and inducible nitric oxide synthase within colorectal tumors: correlation with tumor angiogenesis.

BACKGROUND: Recent studies have shown that the cyclooxygenase (COX) and the inducible nitric oxide synthase (iNOS) pathways are involved in the development of tumor angiogenesis in human cancers. AIMS: To investigate whether a different pattern of COX-2 and iNOS expression/activity exists within different areas of colorectal tumors and to analyze the relationship between these two enzymes and tumor angiogenesis. METHODS: Microvessel density (MVD) and COX-2, iNOS, vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) protein expression were evaluated at both the invasive front (IF) and the tumor center (TC) in 46 human colorectal cancer specimens. We also investigated the concentration of PGE2 and NO at the same sites. RESULTS: COX-2 and iNOS protein expression and activity were significantly higher within the IF than the TC of the tumor specimens. Similarly, MVD and VEGF/VEGFR-2 expression significantly increased from the TC to the IF. Only COX-2 expression was significantly correlated with MVD and VEGF/VEGFR-2 expression at both the TC and the IF. CONCLUSION: Our study shows a heterogeneous expression of COX-2 and iNOS in colorectal cancer. The up-regulation of COX-2 at the IF parallels an increase in vessel density and VEGF/VEGFR-2 expression, thus supporting the hypothesis that the tumor periphery is the most aggressive portion of a colorectal tumor.

GW0742, a high affinity PPAR-ß/δ agonist reduces lung inflammation induced by bleomycin instillation in mice.

Peroxisome Proliferator-Activated Receptor ß/δ belongs to a family of ligand-activated transcription factors. Recent data have clarified its metabolic roles and enhanced the potential role of this receptor as a pharmacological target. Moreover, although its role in acute inflammation remains unclear, being the nuclear receptor PPAR ß/δ widely expressed in many tissues, including the vascular endothelium, we assume that the infiltration of PMNs into tissues, a prominent feature in inflammation, may also be related to PPAR ß/δ. Mice subjected to intratracheal instillation of bleomycin (BLEO, 1 mg/kg), a glycopeptide produced by the bacterium Streptomyces verticillus, develop lung inflammation and injury characterized by a significant neutrophil infiltration and tissue oedema. Therefore, the aim of this study is to investigate the effects of GW0742, a synthetic high affinity PPAR ß/δ agonist, and its possible role in preventing the advance of inflammatory and apoptotic processes induced by bleomycin, that long-term leads to the appearance of pulmonary fibrosis. Our data showed that GW0742-treatment (0.3 mg/Kg, 10 percent DMSO, i.p.) has therapeutic effects on pulmonary damage, decreasing many inflammatory and apoptotic parameters detected by measurement of: 1) cytokine production; 2) leukocyte accumulation, indirectly measured as decrease of myeloperoxidase (MPO) activity; 3) IkBα degradation and NF-kB nuclear translocation; 4) ERK phosphorylation; 5) stress oxidative by NO formation due to iNOS expression; 6) nitrotyrosine and PAR localization; 7) the degree of apoptosis, evaluated by Bax and Bcl-2 balance, FAS ligand expression and TUNEL staining. Taken together, our results clearly show that GW0742 reduces the lung injury and inflammation due to the intratracheal BLEO--instillation in mice.

TNF-alpha as a therapeutic target in inflammatory diseases, ischemia-reperfusion injury and trauma.

Tumor necrosis factor-alpha (TNF-alpha) is a central regulator of inflammation, and TNF-alpha antagonists may be effective in treating inflammatory disorders in which TNF-alpha plays an important pathogenetic role. Recombinant or modified proteins are an emerging class of therapeutic agents. To date, several recombinant or modified proteins which acts as TNF antagonists have been disclosed. In particular, antibodies that bind to and neutralise TNF have been sought as a means to inhibit TNF activity. Inhibition of TNF has proven to be an effective therapy for patients with rheumatoid arthritis and other forms of inflammatory disease including psoriasis, psoriatic arthritis, and ankylosing spondylitis, inflammatory bowel disease. Additionally, the efficacy of preventing septic shock and AIDS has been questioned as a result of recent research. The currently available therapies include a soluble p75 TNF receptor:Fc construct, etanercept, a chimeric monoclonal antibody, infliximab, and a fully human monoclonal antibody, adalimumab. Certolizumab pegol is a novel TNF inhibitor which is an antigen-binding domain of a humanized TNF antibody coupled to polyethylene glycol (PEG) to increase half-life, and thus is Fc-domain-free. In this review, we discuss briefly the present understanding of TNF-alpha-mediated biology and the current therapies in clinical use, and focus on some of the new therapeutic approaches with small-molecule inhibitors. Moreover, we examine recent reports providing important insights into the understanding of efficacy of thalidomide and its analogs, as TNF-alpha activity inhibitories, especially in therapies of several inflammatory diseases within the nervous system.

Effect of PD98059, a selective MAPK3/MAPK1 inhibitor, on acute lung injury in mice.

The aim of the present study is to evaluate the contribution of mitogen-activated protein kinase 1-3 MAPK3/MAPK1) in a model of acute lung inflammation in mice. Injection of carrageenan into the pleural cavity of mice elicited an acute inflammatory response characterized by: accumulation of fluid containing a large number of neutrophils (PMNs) in the pleural cavity, infiltration of PMNs in lung tissues and subsequent adhesion molecule expression (I-CAM and P-selectin), lipid peroxidation, and increased production of tumour necrosis factor-alpha, (TNF-alpha) and interleukin-1beta (IL-1beta). Furthermore, carrageenan induced lung apoptosis (Bax and Bcl-2 expression) as well as nitrotyrosine formation, NF-kB activation, and pJNK expression, as determined by immunohistochemical analysis of lung tissues and the degree of lung inflammation and tissue injury (histological score). Administration of PD98059, an inhibitor of MAPK3/MAPK1 (10 mg/kg) 1 h after carrageenan caused a reduction in all the parameters of inflammation measured. Thus, based on these findings we propose that inhibitors of the MAPK3/MAPK1 signaling pathways, such as PD98059, may be useful in the treatment of various inflammatory diseases.

Effects of the immunomodulator, VGX-1027, in endotoxin-induced uveitis in Lewis rats.

BACKGROUND AND PURPOSE: VGX-1027 is a novel, low molecular weight, immunomodulatory compound that has shown efficacy against a variety of immuno-inflammatory disease models in animals including autoimmune diabetes in NOD mice, collagen-induced arthritis and chemically induced inflammatory colitis. Here, we have studied the effects of VGX-1027 on the development of endotoxin-induced uveitis (EIU) in male Lewis rats, as a model of inflammatory ocular diseases in humans. EXPERIMENTAL APPROACH: EIU was induced by a single footpad injection of 200 microg lipopolysaccharide (LPS). Groups of rats were treated with either VGX-1027 (25 mg kg(-1)) or its vehicle at different time points (30 min, 6 h or 12 h) after the challenge with LPS or, as positive control, with dexamethasone. The rats were killed within 16 h after LPS challenge, and the eyes and aqueous humor were collected to study serological, immunological and histological signs of EIU. KEY RESULTS: The rats treated with VGX-1027 within 6 h after LPS challenge exhibited milder clinical, histological and laboratory signs of EIU than those treated with vehicle. CONCLUSION AND IMPLICATIONS: This study provides the first evidence that systemic treatment with VGX-1027 counteracts the uveitis-inducing effect of LPS in rats and suggests that this drug may have potential in the treatment of immuno-inflammatory conditions of the eye in humans.

Effect of tumour necrosis factor-alpha receptor 1 genetic deletion on carrageenan-induced acute inflammation: a comparison with etanercept.

In the present study, we used tumour necrosis factor-alpha receptor 1 knock-out mice (TNF-alphaR1KO) to evaluate an in vivo role of TNF-alphaR1 on the pathogenesis of inflammatory diseases. We used a murine model of carrageenan-induced acute inflammation (pleurisy), a preclinical model of airway inflammation. The data proved that TNF-alphaR1KO were resistant to carrageenan-induced acute inflammation compared with TNF-alpha wild-type mice. TNF-alphaR1KO showed a significant reduction in accumulation of pleural exudate and in the number of inflammatory cells, in lung infiltration of polymorphonuclear leucocytes and lipid peroxidation and showed a decreased production of nitrite/nitrate in pleural exudates. Furthermore, the intensity and degree of the adhesion molecule intercellular adhesion molecule-1 and P-selectin, Fas ligand (FasL), inducible nitric oxide sythase and nitrotyrosine determined by immunohistochemical analysis were reduced markedly in lung tissues from TNF-alphaR1KO at 4 h and 24 h after carrageenan injection. Moreover, TNF-alpha and interleukin-1beta concentrations were reduced in inflamed areas and in pleural exudates from TNF-alphaR1KO. To support the results generated using pleural inflammation, carrageenan-induced paw oedema models were also performed. In order to elucidate whether the observed anti-inflammatory effects were related to the inhibition of TNF-alpha, we also investigated the effect of etanercept, a TNF-alpha soluble receptor construct, on carrageenan-induced pleurisy. The treatment with etanercept (5 mg/kg subcutaneously 2 h before the carrageenan injection) reduces markedly both laboratory and histological signs of carrageenan-induced pleurisy. Our results showed that administration of etanercept resulted in the same outcome as that of deletion of the TNF-alphaR1 receptor, adding a new insight to TNF-alpha as an excellent target by therapeutic applications.

Role of free radicals and poly(ADP-ribose)polymerase-1 in the development of spinal cord injury: new potential therapeutic targets.

Oxidative stress results from an oxidant/antioxidant imbalance, an excess of oxidants and/or a depletion of antioxidants. A vast amount of circumstantial evidence implicates oxygen-derived free radicals (especially, superoxide and hydroxyl radical) and high energy oxidants (such as peroxynitrite) as mediators of secondary damage associated with spinal cord injury. Reactive oxygen species (ROS) (e.g., superoxide, peroxynitrite, hydroxyl radical and hydrogen peroxide) are all potential reactants capable of initiating DNA single strand breakage, with subsequent activation of the nuclear enzyme poly (ADP ribose) synthetase (PARS), leading to eventual severe energy depletion of the cells, and necrotic-type cell death. Moreover, Poly(ADP-ribosyl)ation is regulated by the synthesizing enzyme poly(ADP-ribose) polymerase-1 (PARP-1) and the degrading enzyme poly(ADP-ribose) glycohydrolase (PARG). Here, we review the roles of ROS, PARP-1 and PARG in spinal cord injury as well as the beneficial effect of the in vivo treatment with novel pharmacological tools (e.g. peroxynitrite decomposition catalysts, selective superoxide dismutase mimetics (SODm), PARP-1 and PARG inhibitors.