In vitro, ex vivo and in vivo immunopharmacological activities of the isoxazoline compound VGX-1027: Modulation of cytokine synthesis and prevention of both organ-specific and systemic autoimmune diseases in murine models

The newly engineered monoclonal antibody ON104, targeting the oxidized Macrophage Migration Inhibitory Factor (oxMIF), ameliorates clinical and histopathological signs of collagen-induced arthritis

Macrophage Migration Inhibitory Factor (MIF) is a pleiotropic inflammatory cytokine that emerged as a pivotal regulator in the pathogenesis of several autoimmune diseases including rheumatoid arthritis (RA). MIF occurs in two immunologically distinct conformational isoforms, indicated as reduced (redMIF) and oxidized MIF (oxMIF) where the latter exerts disease-related activities. In this study we demonstrate the presence of circulating oxMIF in RA patients and investigate the in vivo effects of an oxMIF-neutralizing antibody in a murine model of RA. By advanced antibody engineering we generated the fully human anti-oxMIF antibody ON104 with abolished effector functions. The therapeutic potential of ON104 was tested in a model of Collagen-Induced Arthritis (CIA) in DBA/1j mice. At disease onset, the mice received ON104 twice a week for three weeks. Clinical symptoms were assessed daily, and histological examinations of the joints were performed at the end of the study. Antibody ON104, specifically targeting human and murine oxMIF, is highly affine and does not elicit effector functions in vitro. The treatment of CIA mice with ON104 profoundly modulated disease progression with marked amelioration of clinical signs of arthritis that was associated with reduced synovial and cartilage damage and reduced F4/80-positive macrophages in the joints. These data prove that oxMIF is a relevant target in a well-known model of human RA and its specific neutralization by the antibody ON104 ameliorates clinical and histological signs of the disease in the so-treated mice. Thus, ON104 represents a new and promising treatment option for RA and possibly other autoimmune diseases.

Efficient electrospray deposition of surfaces smaller than the spray plume

Electrospray deposition (ESD) is a promising technique for depositing micro-/nano-scale droplets and particles with high quality and repeatability. It is particularly attractive for surface coating of costly and delicate biomaterials and bioactive compounds. While high efficiency of ESD has only been successfully demonstrated for spraying surfaces larger than the spray plume, this work extends its utility to smaller surfaces. It is shown that by architecting the local "charge landscape", ESD coatings of surfaces smaller than plume size can be achieved. Efficiency approaching 100% is demonstrated with multiple model materials, including biocompatible polymers, proteins, and bioactive small molecules, on both flat and microneedle array targets. UV-visible spectroscopy and high-performance liquid chromatography measurements validate the high efficiency and quality of the sprayed material. Here, we show how this process is an efficient and more competitive alternative to other conformal coating mechanisms, such as dip coating or inkjet printing, for micro-engineered applications.

Distinct effects of different doses of kaempferol on D‑GalN/LPS‑induced ALF depend on the autophagy pathway

Kaempferol, a flavonoid compound, has various biological functions, such as anti-inflammatory and antitumor activities. Acute liver failure (ALF) is a lethal clinical syndrome that occurs due to severe damage of the liver function. In the present study, the mechanisms underlying the therapeutic effects of kaempferol in ALF were evaluated. An ALF mouse model was established using D-galactosamine (D-GalN; 700 mg/kg)/lipopolysaccharide (LPS; 10 µg/kg). A total of 2 h before the administration of D-GalN/LPS, mice were pretreated with different doses of kaempferol (2.5, 5, 10, 20 and 40 mg/kg), and 6 h after injection of D-GalN/LPS, mice were euthanized. The survival rate, liver function and levels of inflammatory cytokines were assessed. The results demonstrated that kaempferol pretreatment protected hepatocytes from ALF induced by D-GalN/LPS via regulation of the autophagy pathway, both in vivo and in vitro. Pretreatment with a high dose of kaempferol significantly decreased the survival rates and increased severe liver damage; however, pretreatment with a low dose of kaempferol had the opposite effect. Furthermore, pretreatment with a high dose of kaempferol enhanced the levels of proinflammatory cytokines [TNF-α, IL-6, IL-12p40, IL-1β, C-X-C motif chemokine ligand (CXCL)-2, CXCL-10] and markers of the MAPK signaling pathway [phosphorylated (p)-JNK, p-ERK, p-p38], whereas pretreatment with a low dose of kaempferol had the opposite effect. Pretreatment with a high dose of kaempferol decreased autophagy, whereas pretreatment with a low dose of kaempferol increased autophagy in vivo and in vitro. It was also shown that pretreatment with 3-methyadenine or autophagy related 7 small interfering RNA, to inhibit autophagy, partially abrogated the hepatoprotective effects of pretreatment with 5 mg/kg kaempferol in the ALF mouse model. These results demonstrate that the effects of different doses of kaempferol on D-GalN/LPS-induced ALF varies based on the dose, and that kaempferol exerted its effects via regulation of the autophagy pathway.

Da-Huang-Fu-Zi-Tang Ameliorates Severe Acute Pancreatitis by Elevation of M2 Kupffer Cells in Rats

Introduction

Severe acute pancreatitis (SAP) is a clinical emergency often accompanied by inflammatory response syndrome (SIRS), which eventually leads to acute lung injury and failure of other organs. The activation of liver Kupffer cells (KCs) plays a major role in the process of SIRS and multiorgan damage caused by SAP. Da-Huang-Fu-Zi-Tang (DHFZT), a traditional Chinese prescription, has been widely used for SAP in the clinic. The present study investigated the activation state of KCs in SAP and the potential mechanism of DHFZT.

Methods

A total of 24 Sprague Dawley rats were randomly assigned to four groups: SH (sham operation group + saline enema), SH-DHFZT (sham operation group + DHFZT enema), SAP (model group + saline enema), and SAP-DHFZT (model group + DHFZT enema). Blood samples were drawn from the abdominal aorta for measuring serum endotoxin, amylase, calcium ion, IL-1β, TNF-α, iNOS, and IL-10. Then, the pancreas, lung, liver, and ileum were harvested for histological observation, and the liver was used to detect the level of F4/80, CD86, and CD163 in KCs with immunohistochemistry and western blot.

Results

In the SAP group, the CD86+ KCs were significantly increased with a high level of IL-1β, TNF-α, and iNOS, and the organs were impaired. In the SAP-DHFZT group, CD163+ KCs were significantly increased with the high level of IL-10, and the damage to organs was alleviated.

Conclusion

These phenomena suggested that the SIRS and multiple organ damage in SAP might be related to the excessive activation of M1 KCs, and DHFZT might alleviate the SIRS by inducing the differentiation of KCs into the M2-type and promote the expression of anti-inflammatory factor IL-10.

Synthesis, Physicochemical Characteristics and Plausible Mechanism of Action of an Immunosuppressive Isoxazolo[5,4-e]-1,2,4-Triazepine Derivative (RM33)

Previous studies demonstrated strong anti-inflammatory properties of isoxazolo[5,4-e]-1,2,4-triazepine (RM33) in vivo. The aim of this investigation was to describe synthesis, determine physicochemical characteristics, evaluate biological activities in murine and human in vitro models, as well as to propose mechanism of action of the compound. The compound was devoid of cell toxicity up to 100 μg/mL against a reference A549 cell line. Likewise, RM33 did not induce apoptosis in these cells. The compound stimulated concanavalin A (ConA)-induced splenocyte proliferation but did not change the secondary humoral immune response in vitro to sheep erythrocytes. Nevertheless, a low suppressive effect was registered on lipopolysaccharide (LPS)-induced splenocyte proliferation and a stronger one on tumor necrosis factor alpha (TNFα) production by rat peritoneal cells. The analysis of signaling pathways elicited by RM33 in nonstimulated resident cells and cell lines revealed changes associated with cell activation. Most importantly, we demonstrated that RM33 enhanced production of cyclooxygenase 2 in LPS-stimulated splenocytes. Based on the previous and herein presented results, we conclude that RM33 is an efficient, nontoxic immune suppressor with prevailing anti-inflammatory action. Additionally, structural studies were carried out with the use of appropriate spectral techniques in order to unequivocally confirm the structure of the RM33 molecule. Unambiguous assignment of NMR chemical shifts of carbon atoms of RM33 was conducted thanks to full detailed analysis of ¹H, ¹³C NMR spectra and their two-dimensional (2D) variants. Comparison between theoretically predicted chemical shifts and experimental ones was also carried out. Additionally, N-deuterated isotopologue of RM33 was synthesized to eliminate potentially disturbing frequencies (such as NH, NH₂ deformation vibrations) in the carbonyl region of the IR (infrared) spectrum to confirm the presence of the carbonyl group.

Targeting pivotal inflammatory pathways in COVID-19: A mechanistic review

As an emerging global health crisis, coronavirus disease 2019 (COVID-19) has been labeled a worldwide pandemic. Growing evidence is revealing further pathophysiological mechanisms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Amongst these dysregulated pathways inflammation seems to play a more critical role toward COVID-19 complications. In the present study, precise inflammatory pathways triggered by SARS-CoV-2, along with potential therapeutic candidates have been discussed. Prevailing evidence has indicated a close correlation of inflammatory cascades with severity, pathological progression, and organ damages in COVID-19 patients. From the mechanistic point of view, interleukin-6, interleukin-1β receptor, interferon-gamma, tumor necrosis factor-alpha receptor, toll-like receptor, receptor tyrosine kinases, growth factor receptor, Janus kinase/signal transducers and transcription pathway, mammalian target of rapamycin, cytokine storm and macrophage activation have shown to play critical roles in COVID-19 complications. So, there is an urgent need to provide novel mechanistic-based anti-inflammatory agents. This review highlights inflammatory signaling pathways of SARS-CoV-2. Several therapeutic targets and treatment strategies have also been provided in an attempt to tackle COVID-19 complications.

Entangling COVID-19 associated thrombosis into a secondary antiphospholipid antibody syndrome: Diagnostic and therapeutic perspectives (Review)

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel β coronavirus that is the etiological agent of the pandemic coronavirus disease 2019 (COVID-19) that at the time of writing (June 16, 2020) has infected almost 6 million people with some 450,000 deaths. These numbers are still rising daily. Most (some 80%) cases of COVID-19 infection are asymptomatic, a substantial number of cases (15%) require hospitalization and an additional fraction of patients (5%) need recovery in intensive care units. Mortality for COVID-19 infection appears to occur globally between 0.1 and 0.5% of infected patients although the frequency of lethality is significantly augmented in the elderly and in patients with other comorbidities. The development of acute respiratory distress syndrome and episodes of thromboembolism that may lead to disseminated intravascular coagulation (DIC) represent the primary causes of lethality during COVID-19 infection. Increasing evidence suggests that thrombotic diathesis is due to multiple derangements of the coagulation system including marked elevation of D-dimer that correlate negatively with survival. We propose here that the thromboembolic events and eventually the development of DIC provoked by SARS-CoV-2 infection may represent a secondary anti-phospholipid antibody syndrome (APS). We will apply both Baconian inductivism and Cartesian deductivism to prove that secondary APS is likely responsible for coagulopathy during the course of COVID-19 infection. Diagnostic and therapeutic implications of this are also discussed.

Effects of GIT-27NO, a NO-donating compound, on hepatic ischemia/reperfusion injury

Hepatic ischemia/reperfusion injury (IRI) is a clinical condition that may lead to cellular injury and organ dysfunction that can be observed in different conditions, such as trauma, shock, liver resection, and transplantation. Moderate levels of nitric oxide (NO) produced by the endothelial isoform of the NO synthase protect against liver IRI. GIT-27NO is a NO-derivative of the toll-like receptor 4 antagonist VGX-1027 that has been shown to possess both antineoplastic and immunomodulatory properties in vitro and in vivo. In this study, we have investigated the effects of this compound in vitro, in a model of oxidative stress induced in HepG2 cells by hydrogen peroxide (H₂O₂), and in vivo, in a rat model of IRI of the liver. GIT-27NO significantly counteracted the toxic effects induced by the H₂O₂ on the HepG2 cells and in vivo, GIT-27NO reduced the transaminase levels and the histological liver injury by reducing necrotic areas with preservation of viable tissue. These effects were almost similar to that of the positive control drug dimethyl fumarate. These data suggest that the beneficial effect of GIT-27NO in the hepatic IRI can be secondary to anti-oxidative effects and hepatocyte necrosis reduction probably mediated by NO release.

Effects of Treatment with the Hypomethylating Agent 5-aza-2'-deoxycytidine in Murine Type II Collagen-Induced Arthritis

The emerging role of epigenetics in the pathogenesis of autoimmune diseases has recently attracted much interest on the possible use of epigenetic modulators for the prevention and treatment of these diseases. In particular, we and others have shown that drugs that inhibit DNA methylation, such as azacitidine (AZA) and decitabine (DAC), already used for the treatment of acute myeloid leukemia, exert powerful beneficial effects in rodent models of type 1 diabetes, multiple sclerosis, and Guillain Barrè syndrome. Along this line of research, we have presently studied the effects of DAC in a murine model of rheumatoid arthritis induced by type II collagen and have demonstrated that DAC administration was associated with a significant amelioration of the clinical condition, along with in vivo and ex vivo modification of the immunological profile of the so-treated mice, that exhibited a diminished production of Th1 and Th17 pro-inflammatory cytokines and reduction of anti-type II collagen autoantibodies.

Expression and function of Toll‑like receptors in peripheral blood mononuclear cells in patients with ankylosing spondylitis

Ankylosing spondylitis (AS) is a common chronic inflammatory autoimmune disease. Toll‑like receptors (TLRs) are involved in non‑specific immunity. In the present study, the roles of TLRs in AS were investigated. The levels of inflammatory cytokines were detected by ELISA and reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). The expression levels of TLRs and nuclear factor‑κB (NF‑κB) signaling‑associated factors were determined via RT‑qPCR and western blot analyses. It was observed that the levels of interleukin (IL)‑6, tumor necrosis factor‑α (TNF‑α), C‑reactive protein, TLR4 and TLR5 were increased in patients with AS, whereas those of IL‑10 and TLR3 were decreased. Pomalidomide, a TNF‑α release inhibitor, reduced the expression of IL‑6, TNF‑α, TLR4, TLR5 and phosphorylated‑p65, and upregulated that of IL‑10, TLR3 and p65 in peripheral blood mononuclear cells from patients with AS. Treatment of patients with infliximab, an anti‑TNF‑α monoclonal antibody, induced similar effects in vivo. In conclusion, it was revealed that inhibition of TNF‑α suppressed inflammatory responses in patients with AS, increased the expression of TLR3 and decreased NF‑κB signaling, and the expression of TLR4 and TLR5. The results indicated that TLRs and the NF‑κB signaling pathway were involved in the regulation of inflammatory responses in AS. These findings provided insight into the mechanisms underlying the development of AS and potential novel therapeutic approaches.

Interleukin-1 beta induces autophagy of mouse preimplantation embryos and improves blastocyst quality

Autophagy is one of the basic cellular mechanism during preimplantation development of mammalian embryos, and it plays crucial role in several physiological processes. It is induced by interleukin (IL)-1β in mammalian cells. Our present study shows that IL-1β is important for autophagy activation in embryo development. Our in vitro culture system analysis shows effect of IL-1β in medium on the development of mouse embryos and it was found to be concentration dependent. A preimplantation embryo culture using medium containing IL-1β did not improve cleavage and blastocyst development rates of mouse embryos; however, blastocyst quality was significantly improved by increasing total cell number, especially in supplementary 20 ng/mL IL-1β. Furthermore, autophagy activation mainly occurs in 2 to 4 cell embryo and blastocyst, 20 ng/mL IL-1β into culture medium can effectively enhance levels of messenger RNA and protein of autophagy-related-factors in 2 to 4 cell embryos and blastocyst, while these factors reduce in VGX-1027 (IL-1β inhibitor) groups that also reduce the quality of blastocyst. Effects of IL-1β on the development of embryo reduced in 20 ng/mL IL-1β supplemented group when 5 mM 3-methyladenine (3-MA) was also added, which used to inhibit autophagy activation in endogenous PtdIns3Ks signal pathway. Our current results show that exogenous IL-1β can effectively induce autophagy in mouse embryos at stages of 2 to 8 cell and blastocyst, that also help to improve the quality of blastocyst.

Protective effect of rivaroxaban on arteriosclerosis obliterans in rats through modulation of the toll-like receptor 4/NF-κB signaling pathway

The aim of the present study was to explore the pharmacological role of rivaroxaban in rats with arteriosclerosis obliterans (ASO) and the potential mechanism of its action. A total of 60 adult male Sprague Dawley (weighing 210–250 g) were randomly assigned into either the sham group, model group or Riv group. Rats in the sham group were fed a normal diet, whereas those in model group and Riv group were fed a high-fat diet for 8 weeks. After establishment of the ASO model, rats in the Riv group were intragastrically administered 10 mg/kg rivaroxaban, whereas those in the sham group and the model group were administrated with the same volume of 0.9% saline for 4 weeks. At the end of animal procedures, a blood sample and the femoral artery of the rats were harvested. The results of the present study revealed that rats in the model group presented with an irregularly narrowed femoral artery lumen, disordered endothelial cells, internal elastic plates and smooth muscle cells. By comparison, the arterial wall structure and stenosis of the femoral artery of rats in Riv group recovered and all the pathological changes were alleviated after rivaroxaban treatment. Levels of total cholesterol, triglycerides and low-density lipoproteins decreased, whereas the level of high-density lipoproteins increased in the Riv group compared with the model group. Rivaroxaban treatment significantly reduced serum levels of interleukin-1, tumor necrosis factor-α and monocyte chemoattractant protein-1 (MCP-1), and increased the serum level of transforming growth factor-β (TGF-β). Rats in the Riv group had reduced expression of toll-like receptor 4 (TLR4), NF-κB and MCP-1, and increased expression of TGF-β in femoral artery tissues compared with the model group. Therefore rivaroxaban may have exerted its anti-atherosclerotic effects by regulating the expression of genes in the TLR4/NF-κB signaling pathway and the activation of the downstream molecules.

Neuroprotective effects of anthocyanins and its major component cyanidin-3-O-glucoside (C3G) in the central nervous system: An outlined review

Anthocyanins, a class of water soluble flavonoids extracted from plants like berries and soybean seed, have been shown to display obvious anti-oxidative, anti-inflammatory, and anti-apoptotic activities. They are recommended as a supplementation for prevention and/or treatment of disorders ranging from cardiovascular disease, metabolic syndrome, and cancer. In the central nervous system (CNS), anthocyanins and its major component cyanidin-3-O-glucoside (C3G) have been reported to produce preventive and/or therapeutic activities in a wide range of disorders, such as cerebral ischemia, Alzheimer's disease, Parkinson's disease, multiple sclerosis, and glioblastoma. Both anthocyanins and C3G can also affect some important processes in aging, including neuronal apoptosis and death as well as learning and memory impairment. Further, the anthocyanins and C3G have been shown to prevent neuro-toxicities induced by different toxic factors, such as lipopolysaccharide, hydrogen peroxide, ethanol, kainic acid, acrolein, glutamate, and scopolamine. Mechanistic studies have shown that inhibition of oxidative stress and neuroinflammation are two critical mechanisms by which anthocyanins and C3G produce protective effects in CNS disorder prevention and/or treatment. Other mechanisms, including suppression of c-Jun N-terminal kinase (JNK) activation, amelioration of cellular degeneration, activation of the brain-derived neurotrophic factor (BDNF) signaling, and restoration of Ca²⁺ and Zn²⁺ homeostasis, may also mediate the neuroprotective effects of anthocyanins and C3G. In this review, we summarize the pharmacological effects of anthocyanins and C3G in CNS disorders as well as their possible mechanisms, aiming to get a clear insight into the role of anthocyanins in the CNS.

Toll-Like Receptor 4-Myeloid Differentiation Primary Response Gene 88 Pathway Is Involved in the Shikonin Treatment of CIA by Regulating Treg/Th17 Expression

OBJECTIVE

To investigate the effect of shikonin on (CIA) collagen-induced arthritis and its influence and mechanism on the balance between Th17 cells and Treg cells.

METHODS

Three doses of shikonin were administered orally to mice before the onset of CIA, and celecoxib was used as positive control drug. The arthritis response was monitored visually by macroscopic scoring and hindpaw swelling. Histology of knee was used to assess the occurrence of cartilage destruction and bone erosion. Serum collagen type II (C II) antibody levels associated with CIA were assessed with ELISAs. RT-PCR and quantitative PCR were employed to determine the mRNA expression of cytokines and TLRs in the surface of DCs in the patella with adjacent synovium and spleen in CIA. The expression of cytokines and transcription factors in the peripheral immune organs was tested by Western blotting.

RESULTS

Shikonin treatment suppressed the macroscopic score and incidence of arthritis. Swelling of hind paws, cartilage destruction, and serum anti-C II concentration were delayed with shikonin when compared to controls. Shikonin treatment suppressed the arthritis in a dose-dependent manner. Moreover, the expression of Th17 cytokines (IL-17A) was greatly inhibited both in the synovium and spleen in treated groups compared with those in control groups. The mRNA and protein levels of IL-10 and TGF-β, however, were upregulated after shikonin treatment. The expression of Foxp3 in the synovium and spleen was upregulated, and the expression of ROR-γt in the synovium and spleen was downregulated after shikonin treatment through RT-PCR, quantitative PCR, and Western blotting. The DCs in the spleen of shikonin-treated mice had lower expression of TLR4 and MyD88, and the expression of TLR2 and TLR9 in the spleen was not different between the two groups.

CONCLUSION

Shikonin has anti-inflammatory effects on CIA. Shikonin treatment can inhibit Th17 cytokines expression and induce Treg responses through inhibiting the activation of TLR4/MyD88 pathway.

Dexamethasone inhibits NF‑кBp65 and HMGB1 expression in the pancreas of rats with severe acute pancreatitis

Severe acute pancreatitis (SAP) starts as a local inflammation of pancreatic tissue that induces the development of multiple extra-pancreatic organ dysfunction; however, the underlying mechanisms remain unclear. The present study was designed to evaluate the effect of dexamethasone (DXM) on pancreatic damage and to investigate the role of high-mobility group box-1 (HMGB1) and nuclear factor-κB (NF-κBp65) in the development of SAP in animal and cell models. For the in vivo experiment, 35 Sprague-Dawley rats were randomly assigned to three groups: The sham-operation control group, the SAP group and the DXM treatment group. Histological analysis revealed that, when DXM was infused into SAP rats, edema formation and structural alterations with necrosis were reduced, and the number of apoptotic cells was markedly reduced. In addition, compared with the SAP group, the expression level of HMGB1 was significantly decreased in the nucleus and the expression level of NF-κBp65 was significantly decreased in the cytoplasm from rats treated with DXM. In vitro, DXM was able to suppress the apoptosis and cell death induced by caerulein (CAE), and DXM could suppress the expression of NF-κBp65 and HMGB1 induced by CAE, as demonstrated by western blotting and immunofluorescence analysis. Therefore, these results provide an experimental basis for investigating the underlying therapeutic mechanisms of DXM treatment for SAP.

Isoxazole Derivatives as Regulators of Immune Functions

In this review, we present reports on the immunoregulatory properties of isoxazole derivatives classified into several categories, such as immunosuppressive, anti-inflammatory, immunoregulatory, and immunostimulatory compounds. The compounds were tested in various models using resident cells from rodents and humans, cell lines, and experimental animal disease models corresponding to human clinical situations. Beneficial features of the described isoxazole derivatives include low toxicity and good bioactivity at low doses. In a majority of studies, the activities of investigated compounds were comparable or even higher than registered reference drugs. Whenever possible, a plausible mechanism of action of the investigated compounds and their potential therapeutic utility were proposed. Among the described compounds, particular attention was paid to the class of immune stimulators with a potential application in chemotherapy patients.

Emerging Role of HMGB1 in the Pathogenesis of Schistosomiasis Liver Fibrosis

In chronic schistosomiasis, liver fibrosis is linked to portal hypertension, which is a condition associated with high mortality and morbidity. High mobility group box 1 (HMGB1) was originally described as a nuclear protein that functions as a structural co-factor in transcriptional regulation. However, HMGB1 can also be secreted into the extracellular milieu under appropriate signal stimulation. Extracellular HMGB1 acts as a multifunctional cytokine that contributes to infection, injury, inflammation, and immune responses by binding to specific cell-surface receptors. HMGB1 is involved in fibrotic diseases. From a clinical perspective, HMGB1 inhibition may represent a promising therapeutic approach for treating tissue fibrosis. In this study, we demonstrate elevated levels of HMGB1 in the sera in experimental mice or in patients with schistosomiasis. Using immunohistochemistry, we demonstrated that HMGB1 trafficking in the hepatocytes of mice suffering from acute schistosomiasis was inhibited by Glycyrrhizin, a well-known HMGB1 direct inhibitor, as well as by DIC, a novel and potential anti-HMGB1 compound. HMGB1 inhibition led to significant downregulation of IL-6, IL4, IL-5, IL-13, IL-17A, which are involved in the exacerbation of the immune response and liver fibrogenesis. Importantly, infected mice that were treated with DIC or GZR to inhibit HMGB1 pro-inflammatory activity showed a significant increase in survival and a reduction of over 50% in the area of liver fibrosis. Taken together, our findings indicate that HMGB1 is a key mediator of schistosomotic granuloma formation and liver fibrosis and may represent an outstanding target for the treatment of schistosomiasis.

Role of Toll-like receptor mediated signaling in traumatic brain injury

The mechanisms underlying secondary brain damage following traumatic brain injury (TBI) remain unclear. A great many studies have demonstrated that inflammatory cascades contribute to brain damage through the activation of immune/inflammatory responses, including the increased release of cytokines and chemokines, and the recruitment of leukocytes. The cells and tissues damaged by primary mechanical injury release a number of endogenous factors acting as damage-associated molecular patterns (DAMPs), which initiate and perpetuate noninfectious inflammatory responses through transduction signaling pathways. Toll-like receptors (TLRs) are a transmembrane receptor family that can recognize the specific DAMPs released from damaged cells and recruit a set of adaptors leading to the activation of downstream kinases and nuclear factors which regulate the expression of inflammatory genes. The activation of inflammatory responses mediated by TLR signaling is closely associated with brain tissue damage and neurological dysfunction following TBI. TLRs and their downstream protein kinases may be potential targets for the treatment of TBI. Modulation of TLR-mediated signaling may attenuate brain damage and improve TBI outcome. In this review, we briefly discuss the role of TLR-mediated signaling in TBI and the new treatments targeting TLR signaling. This article is part of the Special Issue entitled "Novel Treatments for Traumatic Brain Injury".

The involvement of neuroinflammation and necroptosis in the hippocampus during vascular dementia

The prevalence of vascular dementia is increasing at an alarming rate. The Confirmation of the clinical diagnosis of vascular dementia depends on post-mortem examination of the brain. In our study, we investigated the vascular disease and neuroinflammation during vascular dementia. Our results showed a β-amyloid deposits, neovascularization, neuronal hypertrophy and neuroinflammation in the hippocampus tissue. Interestingly, the neuroinflammation was characterized by a higher expression of TNF-α, IL-1β, TGF-β and iNOS which are TLR4/RelA pathway dependent. Finally, the finding of necroptosis by impaired blood supply and inflammation state suggests that the cognitive impairment was caused by vascular disease and neuroinflammation.

DFMG attenuates the activation of macrophages induced by co‑culture with LPC‑injured HUVE‑12 cells via the TLR4/MyD88/NF‑κB signaling pathway

7‑difluoromethoxy‑5,4'‑dimethoxy‑genistein (DFMG) is a novel active chemical entity, which modulates the function and signal transduction of endothelial cells and macrophages (MPs), and is essential in the prevention of atherosclerosis. In the present study, the activity and molecular mechanism of DFMG on MPs was investigated using a Transwell assay to construct a non‑contact co‑culture model. Human umbilical vein endothelial cells (HUVE‑12), which were incubated with lysophosphatidylcholine (LPC), were seeded in the upper chambers, whereas PMA‑induced MPs were grown in the lower chambers. The generation of reactive oxygen species (ROS) and the release of lactate dehydrogenase (LDH) were measured using the corresponding assay kits. The proliferation and migration were assessed using 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide and wound healing assays, respectively. Foam cell formation was examined using oil red O staining and a total cholesterol assay. The protein expression levels of Toll‑like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and nuclear factor (NF)‑κB p65 were detected by western immunoblotting. The secretion of interleukin (IL)‑1β was examined using an enzyme‑linked immunosorbent assay. It was found that LPC significantly increased the generation of ROS and the release of LDH in HUVE‑12 cells. The LPC‑injured HUVE‑12 cells activated MPs under co‑culture conditions and this process was inhibited by DFMG treatment. LPC upregulated the expression levels of TLR4, MyD88 and NF‑κB p65, and the secretion of IL‑1β in the supernatant of the co‑cultured HUVE‑12 cells and MPs. These effects were reversed by the application of DFMG. Furthermore, CLI‑095 and IL‑1Ra suppressed the activation of MPs that was induced by co‑culture with injured HUVE‑12 cells. These effects were further enhanced by co‑treatment with DFMG, and DFMG exhibited synergistic effects with a TLR4‑specific inhibitor. Take together, these findings revealed that DFMG attenuated the activation of MP induced by co‑culture with LPC‑injured HUVE‑12 cells. This process was mediated via inhibition of the TLR4/MyD88/NF‑κB signaling pathway in HUVE‑12 cells.

Calcium supplementation decreases BCP-induced inflammatory processes in blood cells through the NLRP3 inflammasome down-regulation

Interaction of host blood with biomaterials is the first event occurring after implantation in a bone defect. This study aimed at investigating the cellular and molecular consequences arising at the interface between whole blood and biphasic calcium phosphate (BCP) particles. We observed that, due to calcium capture, BCP inhibited blood coagulation, and that this inhibition was reversed by calcium supplementation. Therefore, we studied the impact of calcium supplementation on BCP effects on blood cells. Comparative analysis of BCP and calcium supplemented-BCP (BCP/Ca) effects on blood cells showed that BCP as well as BCP/Ca induced monocyte proliferation, as well as a weak but significant hemolysis. Our data showed for the first time that calcium supplementation of BCP microparticles had anti-inflammatory properties compared to BCP alone that induced an inflammatory response in blood cells. Our results strongly suggest that the anti-inflammatory property of calcium supplemented-BCP results from its down-modulating effect on P2X7R gene expression and its capacity to inhibit ATP/P2X7R interactions, decreasing the NLRP3 inflammasome activation. Considering that monocytes have a vast regenerative potential, and since the excessive inflammation often observed after bone substitutes implantation limits their performance, our results might have great implications in terms of understanding the mechanisms leading to an efficient bone reconstruction.

STATEMENT OF SIGNIFICANCE

Although scaffolds and biomaterials unavoidably come into direct contact with blood during bone defect filling, whole blood-biomaterials interactions have been poorly explored. By studying in 3D the interactions between biphasic calcium phosphate (BCP) in microparticulate form and blood, we showed for the first time that calcium supplementation of BCP microparticles (BCP/Ca) has anti-inflammatory properties compared to BCP-induced inflammation in whole blood cells and provided information related to the molecular mechanisms involved. The present study also showed that BCP, as well as BCP/Ca particles stimulate monocyte proliferation. As monocytes represent a powerful target for regenerative therapies and as an excessive inflammation limits the performance of biomaterials in bone tissue engineering, our results might have great implications to improve bone reconstruction.

Ethyl Acetate Extract of Origanum vulgare L. ssp. hirtum Prevents Streptozotocin-Induced Diabetes in C57BL/6 Mice

Type 1 diabetes (T1D) is an autoimmune disease that develops as a consequence of pancreatic β-cell death induced by proinflammatory mediators. Because Origanum vulgare L. ssp. hirtum (Greek oregano) contains antiinflammatory molecules, we hypothesized that it might be beneficial for the treatment of T1D. An ethyl acetate extract of oregano (EAO) was prepared from the leaves by a polar extraction method. Phytochemical composition was determined by liquid chromatography-UV diode array coupled to ion-trap mass spectrometry with electrospray ionization interface (LC/DAD/ESI-MS(n) ). In vitro immunomodulatory effect of EAO was estimated by measuring proliferation (MTT) or cytokine secretion (ELISA) from immune cells. Diabetes was induced by multiple low doses of streptozotocin (MLDS) in male C57BL/6 mice and EAO was administered intraperitoneally for 10 d. Determination of cellular composition (flow cytometry) and cytokine production (ELISA) was performed on 12th d after diabetes induction. EAO suppressed the function of both macrophages and lymphocytes in vitro. In vivo, EAO treatment significantly preserved pancreatic islets and reduced diabetes incidence in MLDS-challenged mice. Besides down-modulatory effect on macrophages, EAO reduced the number of total CD4(+) and activated CD4(+) CD25(+) T cells. Furthermore, EAO affected the number of T helper 1 (Th1) and T helper 17 (Th17) cells through downregulation of their key transcription factors T-bet and RORγT. Because EAO treatment protects mice from development of hyperglycemia by reducing proinflammatory macrophage/Th1/Th17 response, this plant extract could represent a basis for future diabetes therapy.

A case for IL-6, IL-17A, and nitric oxide in the pathophysiology of Sjögren's syndrome

Sjögren's syndrome (SS) is an autoimmune epithelitis characterized by mononuclear cell (MNC) infiltration of the lacrimal and salivary glands (SG), as well as the presence of serum autoantibodies. This condition is a growing public health concern in Algeria. Herein, we sought to determine if the levels of interleukin (IL)-6, IL-17A, and nitric oxide (NO), were correlated with the extent of MNC infiltration. The expression of inducible NO synthase (NOS2) and CD68 was measured in the SG of all patients, but not in those of the normal controls (NCs). We included 44 primary Sjögren's syndrome (pSS) patients and 15 NCs in this study; we found that the expression of NOS2 and CD68 was elevated in all of the SG of SS patients. Additionally, the serum and saliva levels of IL-6, IL-17A, and NO were higher in the pSS patients, compared with the NCs. Furthermore, the NOS2-induced excess NO was associated with the extent of the MNC infiltration, and thereby with tissue injury. It is also important to note that there were correlations between the levels of IL-6, IL-17A, and NO. Such findings indicate that through the effects of NO, IL-17A participates in the pathophysiology of the disease. With the purpose of improving both the diagnosis and prognosis, IL-6, IL-17A, and NO should be assayed in the serum and saliva of patients suspected of SS.

Inhibition of MDM2 expression by rosmarinic acid in TSLP-stimulated mast cell

Rosmarinic acid (RA) has an anti-inflammatory property while thymic stromal lymphopoietin (TSLP) has an important role in mast cell-mediated inflammatory responses. Thus, the aim of this study was to determine the regulatory effect of RA in TSLP-stimulated human mast cell line, HMC-1 cells, and short ragweed pollen-induced allergic conjunctivitis mouse model. As a result, we found that RA significantly decreased the TSLP-induced mast cell proliferation and murine double minute (MDM) 2 expression. RA significantly decreased the levels of interleukin (IL)-13 and phosphorylated the signal transducer and activation of transcription 6 in the TSLP-stimulated HMC-1 cells. RA induced the increment of p53 levels, caspase-3 activation, and poly-ADP-ribose polymerase cleavage and the reduction of the procaspase-3 and Bcl2. RA significantly reduced the production of tumor necrosis factor-α, IL-1β, and IL-6 on the TSLP-stimulated HMC-1 cells. In addition, RA significantly reduced the levels of IgE, IL-4, and TSLP in the short ragweed pollen-induced allergic conjunctivitis mouse model. In conclusion, the results of the study suggest that RA has a significant anti-inflammatory effect on TSLP-induced inflammatory reactions. These effects of RA are likely to be mediated through inhibiting the MDM2 increased by TSLP.

Ti–O based nanomaterials ameliorate experimental autoimmune encephalomyelitis and collagen-induced arthritis

Administration of Ti–O based nanomaterials ameliorated the clinical severity of experimental autoimmune encephalomyelitis and collagen induced arthritis, thus provide novel therapeutic approach for multiple sclerosis and rheumatoid arthritis.

Atractylenolide I protects mice from lipopolysaccharide-induced acute lung injury

Atractylenolide I (AO-I), one of the major bioactive components isolated from Rhizoma Atractylodes macrocephala, has been reported to have anti-inflammatory effects. In the present study, we investigated the protective effects of AO-I on acute lung injury (ALI) using LPS-induced ALI mouse model. Lung injury was assessed by histological study. Inflammatory cytokines TNF-α, IL-6 and IL-1β production were detected by ELISA. TLR4 expression and NF-κB activation were measured by western blot analysis. The results showed that treatment of AO-I significantly attenuated LPS-induced lung wet-to-dry weight ratio and MPO activity. Meanwhile, treatment of AO-I significantly inhibited the production of TNF-α, IL-6, IL-1β, IL-13, and MIF production in bronchoalveolar lavage fluid (BALF), as well as neutrophils and macrophages in BALF. AO-1 could up-regulate the production of IL-10 in BALF. Besides, LPS-induced TLR4 expression and NF-κB activation were suppressed by treatment of AO-I. In conclusion, the current study suggested that AO-I protected mice acute lung injury induced by LPS via inhibition of TLR4 expression and NF-κB activation.

Safety, bioavailability, and pharmacokinetics of VGX-1027-A novel oral anti-inflammatory drug in healthy human subjects

VGX-1027, a novel oral immune modulator, is under development for the treatment of rheumatoid arthritis. The safety, tolerability, and pharmacokinetics of single (1-800 mg) and multiple (40-400 mg) oral doses were evaluated in 2 clinical studies. The doses were well tolerated up to 800 mg in a single dose and 200 mg twice daily in multiple doses. Adverse events were mild to moderate in severity with no identifiable dose-related pattern. There were no clinically significant physical or laboratory findings. The pharmacokinetic data indicated that increases in Cmax and AUC0-inf were dose-proportional, and AUC0- τ was approximately dose-proportional. For the single-dose study, median Tmax ranged from 0.5 to 2 hours and mean t1/2 ranged from 4.9 to 8.7 hours. For the multiple-dose study, median Tmax ranged from 0.5 to 2.0 hours and mean t1/2 ranged from 7.05 to 10.05 hours. No accumulation of the drug was observed after day 1, indicating that steady-state concentrations were attained with single and multiple dosing for 5 days. Approximately 90% of the administered dose was excreted in urine as unchanged drug.

Podocyte apoptosis is prevented by blocking the Toll-like receptor pathway

High serum lipopolysaccharide (LPS) activity in normoalbuminuric patients with type 1 diabetes (T1D) predicts the progression of diabetic nephropathy (DN), but the mechanisms behind this remain unclear. We observed that treatment of cultured human podocytes with sera from normoalbuminuric T1D patients with high LPS activity downregulated 3-phosphoinositide-dependent kinase-1 (PDK1), an activator of the Akt cell survival pathway, and induced apoptosis. Knockdown of PDK1 in cultured human podocytes inhibited antiapoptotic Akt pathway, stimulated proapoptotic p38 MAPK pathway, and increased apoptosis demonstrating an antiapoptotic role for PDK1 in podocytes. Interestingly, PDK1 was downregulated in the glomeruli of diabetic rats and patients with type 2 diabetes before the onset of proteinuria, further suggesting that reduced expression of PDK1 associates with podocyte injury and development of DN. Treatment of podocytes in vitro and mice in vivo with LPS reduced PDK1 expression and induced apoptosis, which were prevented by inhibiting the Toll-like receptor (TLR) signaling pathway with the immunomodulatory agent GIT27. Our data show that LPS downregulates the cell survival factor PDK1 and induces podocyte apoptosis, and that blocking the TLR pathway with GIT27 may provide a non-nephrotoxic means to prevent the progression of DN.

VGX-1027 modulates genes involved in lipopolysaccharide-induced Toll-like receptor 4 activation and in a murine model of systemic lupus erythematosus

VGX-1027 [(S,R)-3-phenyl-4,5-dihydro-5-isoxasole acetic acid] is a small molecule compound with immunomodulatory properties, which favourably influences the development of immuno-inflammatory and autoimmune diseases in different animal models such as type 1 diabetes mellitus, pleurisy, rheumatoid arthritis and inflammatory bowel disease. However, the precise mechanism of action of VGX-1027 remains to be ascertained. With this aim, we have studied the immunomodulatory effects of VGX-1027 in vitro, using a genome-wide oligonucleotide microarray approach, and in vivo, using the NZB/NZW F1 model of systemic lupus erythematosus. Microarray data revealed that the administration of VGX-1027 profoundly affected the immune response to exogenous antigens, by modulating the expression of genes that are primarily involved in antigen processing and presentation as well as genes that regulate immune activation. When administered in vivo VGX-1027 ameliorated the course of the disease in the NZB/NZW F1 mice, which correlated with higher per cent survival and improved clinical and histopathological signs. The data presented herein support the theory that VGX-1027 modulates immunity, probably by inhibiting inflammatory antigen presentation and so limiting immune cell expansion.

Effects of Toll-like receptor antagonist 4,5-dihydro-3-phenyl-5-isoxasole acetic acid on the progression of kidney disease in mice on a high-fat diet

BACKGROUND

Obesity-related metabolic disorders are closely associated with inflammation induced by innate immunity. Toll-like receptors (TLRs) play a pivotal role in the innate immune system by activating proinflammatory signaling pathways. GIT27 (4,5-dihydro-3-phenyl-5-isoxasole acetic acid) is an active immunomodulatory agent that primarily targets macrophages and inhibits secretion of tumor necrosis factor α [as well as interleukin (IL)-1β, IL-10, and interferon γ]. However, the effect of TLR antagonist on kidney diseases has rarely been reported. We investigated whether the TLR antagonist GIT27 has beneficial effects on the progression of kidney disease in obese mice on a high-fat diet (HFD).

METHODS

Six-week-old male C57BL/6 mice were divided into three groups: mice fed with normal chow diet (N=4); mice fed with a HFD (60% of total calories from fat, 5.5% from soybean oil, and 54.5% from lard, N=4); and GIT27-treated mice fed with a HFD (N=7).

RESULTS

Glucose intolerance, oxidative stress, and lipid abnormalities in HFD mice were improved by GIT27 treatment. In addition, GIT27 treatment decreased the urinary excretion of albumin and protein in obesity-related kidney disease, urinary oxidative stress markers, and inflammatory cytokine levels. This treatment inhibited the expression of proinflammatory cytokines in the kidneys and adipose tissue, and improved extracellular matrix expansion and tubulointerstitial fibrosis in obesity-related kidney disease.

CONCLUSION

TLR inhibition by administering GIT27 improved metabolic parameters. GIT27 ameliorates abnormalities of lipid metabolism and may have renoprotective effects on obesity-related kidney disease through its anti-inflammatory properties.

High mobility group box protein-1 promotes cerebral edema after traumatic brain injury via activation of toll-like receptor 4

Traumatic brain injury (TBI) is a major cause of mortality and morbidity worldwide. Cerebral edema, a life-threatening medical complication, contributes to elevated intracranial pressure (ICP) and a poor clinical prognosis after TBI. Unfortunately, treatment options to reduce post-traumatic edema remain suboptimal, due in part, to a dearth of viable therapeutic targets. Herein, we tested the hypothesis that cerebral innate immune responses contribute to edema development after TBI. Our results demonstrate that high-mobility group box protein 1 (HMGB1) was released from necrotic neurons via a NR2B-mediated mechanism. HMGB1 was clinically associated with elevated ICP in patients and functionally promoted cerebral edema after TBI in mice. The detrimental effects of HMGB1 were mediated, at least in part, via activation of microglial toll-like receptor 4 (TLR4) and the subsequent expression of the astrocytic water channel, aquaporin-4 (AQP4). Genetic or pharmacological (VGX-1027) TLR4 inhibition attenuated the neuroinflammatory response and limited post-traumatic edema with a delayed, clinically implementable therapeutic window. Human and rodent tissue culture studies further defined the cellular mechanisms demonstrating neuronal HMGB1 initiates the microglial release of interleukin-6 (IL-6) in a TLR4 dependent mechanism. In turn, microglial IL-6 increased the astrocytic expression of AQP4. Taken together, these data implicate microglia as key mediators of post-traumatic brain edema and suggest HMGB1-TLR4 signaling promotes neurovascular dysfunction after TBI.

Renal protective effects of toll-like receptor 4 signaling blockade in type 2 diabetic mice

Chronic inflammation caused by high glucose and high free fatty acid (FFA) concentrations is a major contributor to the pathogenesis of type 2 diabetes. Recent evidence suggests that activation of Toll-like receptor (TLR) signaling induces peripheral insulin resistance and mediates central insulin and leptin resistance. In this study, we investigated the renal effects of TLR4 signaling blockade in type 2 diabetic mice. Eight-week-old db/db mice were treated for 12 weeks with (S,R)-3-phenyl-4,5-dihydro-5-isoxasole acetic acid (GIT27), which targets macrophages through the inhibition of TLR4- and TLR2/6-mediated signaling pathways. Although GIT27 treatment improved glycemic control and insulin tolerance, which is associated with a lower lipid profile, it did not impact body weight or food consumption. GIT27 treatment also markedly decreased urinary albumin excretion, decreased proinflammatory cytokine synthesis, improved tissue lipid metabolism, induced oxidative stress, and improved glomerulosclerosis compared with the control db/db group. In cultured podocytes and adipocytes, high glucose levels with FFA stimulation increased TLR4 expression and proinflammatory cytokine synthesis, but the effects were abolished by GIT27 treatment. In addition, knockdown of TLR4 expression by stealth small interfering RNA abolished FFA-induced proinflammatory cytokine synthesis in cultured podocytes. In conclusion, our results suggest that GIT27 treatment improves insulin resistance and protects against the renal injury that occurs in type 2 diabetic nephropathy through both metabolic and antiglomerulosclerotic mechanisms. These results suggest that TLR pathway inhibition might play a direct protective role in diabetic kidney disease.

Therapeutic potential of nitric oxide-modified drugs in colon cancer cells

We have examined the influence of the nitric oxide (NO)-modified anti-inflammatory drug (S,R)-3-phenyl-4,5-dihydro-5-isoxasole acetic acid (VGX-1027) named GIT-27NO or the NO-modified antiviral drug saquinavir (Saq) named Saq-NO on two colon cancer cell lines, mouse CT26CL25 and human HCT116. The effects of the drugs on cell viability, apoptosis, proliferation, and metastatic potential were analyzed. The release of NO and oxygen and nitrogen species was also determined. The efficacy of the drugs was evaluated in vivo in BALB/c mice injected with CT26CL25 cells. Both agents suppressed the growth of colon cancer cells in vitro and reduced tumor volume in syngeneic BALB/c mice. However, their mechanisms of action were different because GIT-27NO released larger amounts of nitrite than Saq-NO in cell cultures and its antitumor action depended on the intracellular NO release inside the cells. On the contrary, Saq-NO released barely detectable amounts of NO and its antitumor action was NO-independent. In fact, cotreatment with an NO-peroxynitrite scavenger revealed that GIT-27NO but not Saq-NO acts through peroxynitrite-mediated cell destruction. At the cellular level, GIT-27NO prevalently induced proapoptotic signals followed by caspase-dependent apoptosis. In contrast, Saq-NO blocked cell proliferation, changed the adhesive, migratory, and invasive properties of the cells, and decreased metastatic potential in vivo. In conclusion, differences in NO release and oxidative stress generation between GIT-27NO and Saq-NO resulted in different mechanisms that caused cell death.

Evaluation of 3-(3-chloro-phenyl)-5-(4-pyridyl)-4,5-dihydroisoxazole as a novel anti-inflammatory drug candidate

BACKGROUND

3-(3-chloro-phenyl)-5-(4-pyridyl)-4,5-dihydroisoxazole (DIC) is a five-membered heterocyclic compound containing a N-O bond. The anti-inflammatory effects of this compound were studied both in vitro and in vivo.

PRINCIPAL FINDINGS

DIC effectively decreased TNF-α and IL-6 release from LPS-stimulated macrophages in a dose dependent manner. DIC diminished the levels of COX-2 with subsequent inhibition of PGE(2) production. DIC also compromised HMGB1 translocation from the nucleus to the cytoplasm. Moreover, DIC prevented the nuclear translocation of NF-κB and inhibited the MAPK pathway. In vivo, DIC inhibited migration of neutrophils to the peritoneal cavity of mice.

CONCLUSIONS

This study presents the potential utilization of a synthetic compound, as a lead for the development of novel anti-inflammatory drugs.

Targeting innate immunity protein kinase signalling in inflammation

Inflammation is an evolutionarily conserved host reaction that is initiated in response to trauma, tissue damage and infection. It leads to changes in tissue homeostasis and blood flow, immune-cell activation and migration, and secretion of cytokines and mediators in a spatio-temporally coordinated manner. Progress in understanding of the mechanisms of the inflammatory response has identified various protein kinases that act as essential signalling components and therefore represent potential therapeutic targets. This article summarizes advances in the identification and validation of such targets, and discusses key issues for the development of small-molecule kinase inhibitors as a new generation of oral anti-inflammatory drugs, including feedback loops, inhibitor specificity and combination therapy.

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.

Anticancer properties of the novel nitric oxide-donating compound (S,R)-3-phenyl-4,5-dihydro-5-isoxazole acetic acid-nitric oxide in vitro and in vivo

Preclinical studies have shown that nitric oxide (NO)-donating nonsteroidal anti-inflammatory drugs possess anticancer activities. Here, we report in vitro and in vivo studies showing the antitumor effect of the NO-donating isoxazole derivative (S,R)-3-phenyl-4,5-dihydro-5-isoxazole acetic acid (GIT-27NO). GIT-27NO, but not the NO-deprived parental compound VGX-1027, significantly affected viability of both rodent (L929, B16, and C6) and human (U251, BT20, HeLa, and LS174) tumor cell lines. GIT-27NO triggered either apoptotic cell death (e.g., L929 cells) or autophagic cell death (C6 and B16 cells). Moreover, GIT-27NO hampered the viability of cisplatin-resistant B16 cells. NO scavenger hemoglobin completely prevented GIT-27NO-induced death, indicating that NO release mediated the tumoricidal effect of the compound. Increase in intracellular NO upon on the treatment was associated with intensified production of reactive oxygen species, whereas their neutralization by antioxidant N-acetylcysteine resulted in partial recovery of cell viability. The antitumor activity of the drug was mediated by the selective activation of mitogen-activated protein kinases in a cell-specific manner and was neutralized by their specific inhibitors. In vivo treatment with GIT-27NO significantly reduced the B16 melanoma growth in syngeneic C57BL/6 mice. The therapeutic effect occurred at dose (0.5 mg/mouse) up to 160 times lower than those needed to induce acute lethality (80 mg/mouse). In addition, a dose of GIT-27NO five times higher than that found effective in the melanoma model was well tolerated by the mice when administered for 4 consecutive weeks. These data warrant additional studies to evaluate the possible translation of these findings to the clinical setting.