Effects of antioxidants and nitric oxide on TNF-α-induced adhesion molecule expression and NF-κB activation in human dermal microvascular endothelial cells

Spermidine Exerts Protective Effects in Random-Pattern Skin Flap Survival in Rats: Possible Involvement of Inflammatory Cytokines, Nitric Oxide, and VEGF

BACKGROUND

Distal necrosis and inflammation are two of the most common health consequences of random-pattern skin flaps survival (SFS). Anti-inflammatory effects of spermidine have been identified in various studies. On the other hand, considering the involvement of the nitric oxide molecule in the spermidine mode of action and also its role in skin tissue function, we analyzed the possible effects of spermidine on the SFS and also, potential involvement of nitrergic pathway and inflammatory cytokine in these phenomena.

METHODS

Each rat was pretreated with either a vehicle (control) or various doses of spermidine (0.5, 1, 3, 5, 10 and 30 mg/kg) and then was executed a random-pattern skin flap paradigm. Also, spermidine at the dose of 5 mg/kg was selected and one group rats received spermidine 20 min prior to surgery and one additional dose 1 day after operation. Then, 7 days after operations, interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon-gamma (IFN-γ), and nitrite levels were inquired in the tissue samples by ELIZA kit. Vascular endothelial growth factor expression was assessed by DAPI staining and fluorescent microscopes. The concentrations of three polyamines, including spermidine, spermine, and cadaverine, were analyzed using HPLC.

RESULTS

Pretreatment with spermidine 5 mg/kg improved SFS considerably in microscopic skin H&E staining analysis and decreased the percentage of necrotic area. Moreover, spermidine exerted promising anti-inflammatory effects via the modulation of nitric oxide and reducing inflammatory cytokines.

CONCLUSIONS

Spermidine could improve skin flaps survival, probably through the nitrergic system and inflammation pathways. This preclinical study provides level III evidence for the potential therapeutic effects of spermidine on SFS in rats, based on the analysis of animal models. Further studies are needed to confirm these findings in clinical settings.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Safety of Anti-Reelin Therapeutic Approaches for Chronic Inflammatory Diseases

Reelin, a large extracellular glycoprotein, plays critical roles in neuronal development and synaptic plasticity in the central nervous system (CNS). Recent studies have revealed non-neuronal functions of plasma Reelin in inflammation by promoting endothelial-leukocyte adhesion through its canonical pathway in endothelial cells (via ApoER2 acting on NF-κB), as well as in vascular tone regulation and thrombosis. In this study, we have investigated the safety and efficacy of selectively depleting plasma Reelin as a potential therapeutic strategy for chronic inflammatory diseases. We found that Reelin expression remains stable throughout adulthood and that peripheral anti-Reelin antibody treatment with CR-50 efficiently depletes plasma Reelin without affecting its levels or functionality within the CNS. Notably, this approach preserves essential neuronal functions and synaptic plasticity. Furthermore, in mice induced with experimental autoimmune encephalomyelitis (EAE), selective modulation of endothelial responses by anti-Reelin antibodies reduces pathological leukocyte infiltration without completely abolishing diapedesis. Finally, long-term Reelin depletion under metabolic stress induced by a Western diet did not negatively impact the heart, kidney, or liver, suggesting a favorable safety profile. These findings underscore the promising role of peripheral anti-Reelin therapeutic strategies for autoimmune diseases and conditions where endothelial function is compromised, offering a novel approach that may avoid the immunosuppressive side effects associated with conventional anti-inflammatory therapies.

Effect of Astaxanthin on Anti-Inflammatory and Anti-Oxidative Effects of Astaxanthin Treatment for Atopic Dermatitis-induced Mice

Background: This study sought to determine whether the antioxidant effects of astaxanthin (AST) could have an anti-inflammatory effect to reduce inflammation caused by atopic dermatitis (AD).Methods: Using a mouse model of AD induced by phtalic acid (PA), the levels of inflammation, inflammatory agents, and evidence of antioxidant activity were examined in PA treated mice (n = 3), PA-AST treated mice (n = 3), and a control group of mice (n = 3). This included measurements of ear thickness, levels of mast cells, IgE, inflammatory cytokine, malondialdehyde (MDA), hydrogen peroxide, HO-1, and GPx-1.Results: AST treatment significantly prevented inflammation as measured by ear thickness (<i>p</i> < 0.05), mast cell count (<i>p</i> < 0.001), and IgE concentration in the blood (<i>p</i> < 0.001). Levels of TNF-α (<i>p</i> < 0.001), IL-1β (<i>p</i> < 0.001), IL-6 (<i>p</i> < 0.001), and MDA (<i>p</i> < 0.05) were also significantly lower. In addition, GSH levels increased significantly (<i>p</i> < 0.001), and the level of hydrogen peroxide significantly reduced (<i>p</i> < 0.01). The expression of HO-1, GPx-1 increased.Conclusion: In this small experimental study, AST acted on inflammatory mechanisms that induced AD, through anti-inflammatory and antioxidant mechanisms, and is a candidate of interest in the clinical treatment of AD.

Therapeutic potential of topically administered γ-AlOOH on 2,4-dinitrochlorobenzene-induced atopic dermatitis-like lesions in Balb/c mice

Boehmite (γ-AlOOH) has a wide range of applications in a variety of industrial and biological fields. However, little is known about its potential roles in skin diseases. The current study investigated its effect on atopic dermatitis (AD). Following characterization, cytotoxicity, pro-inflammatory response and oxidative stress associated with boehmite were assessed, using TNF-α-induced keratinocytes and mast cells. In addition, therapeutic effects of boehmite, topically administered to Balb/c mice induced by 2,4-dinitrochlorobenzene (DNCB), were evaluated. Expression of cytokines (TLSP, IL-25 and IL-33) and the generation of ROS from keratinocytes induced by TNF-α were significantly inhibited by boehmite without affecting cell viability. MAPKs (ERK, JNK and p38) required for cytokine expression were suppressed by boehmite treatment. Up-regulation of cytokines (TSLP, IL-4, IL-5, IL-13, RANTES) in human mast cells treated with phorbol 12-myristate 13-acetate and calcium ionophore was also suppressed by boehmite. Boehmite improved the AD severity score, epidermal hyperplasia and transepidermal water loss in DNCB-induced AD-like lesions. Moreover, Th2-mediated cytokine expression, mast cell hyperplasia and destruction of the skin barrier were improved by boehmite treatment. Overall, we demonstrated that boehmite may potentially protect against AD.

NO-Donor Nitrosyl Iron Complex with 2-Aminophenolyl Ligand Induces Apoptosis and Inhibits NF-κB Function in HeLa Cells

NO donating iron nitrosyl complex with 2-aminothiophenyl ligand (2-AmPh complex) was studied for its ability to cause cell death and affect nuclear factor kappa B (NF-κB) signaling. The complex inhibited viability of HeLa cells and induced cell death that was accompanied by loss of mitochondrial membrane potential and characteristic for apoptosis phosphatidylserine externalization. At IC50, 2-AmPh caused decrease in nuclear content of NF-κB p65 polypeptide and mRNA expression of NF-κB target genes encoding interleukin-8 and anti-apoptotic protein BIRC3. mRNA levels of interleukin-6 and anti-apoptotic protein BIRC2 encoding genes were not affected. Our data demonstrate that NO donating iron nitrosyl complex 2-AmPh can inhibit tumor cell viability and induce apoptosis that is preceded by impairment of NF-κB function and suppression of a subset of NF-κB target genes.

[Effects of Blending Oil of Lavender and Thyme on Oxidative Stress, Immunity, and Skin Condition in Atopic Dermatitis Induced Mice]

PURPOSE

The purpose of this study was to evaluate the effects of essential oil on oxidative stress, immunity, and skin condition in atopic dermatitis (AD) induced mice.

METHODS

This study was a 3×3 factorial design. Factors were oil type (Lavender, Thyme, and 2:1 mixture of lavender and thyme oil [blending oil]) and treatment period (0 day, 7 days, and 21 days). The samples were 45 mice with AD and randomly assigned to nine groups of five mice per group. The dependent variables such as superoxide radical, IgE, degranulated mast cells, and epidermal thickness were measured. Data were collected from February to April in 2014. Descriptive statistics, One-way ANOVA, Two-way ANOVA, and Tukey's HSD test were performed using the SPSS WIN 20.0 program.

RESULTS

Dependent variables were not statistically significantly different by the three oil types (p>.05). Essential oils such as lavender, thyme, and blending oil were all effective in reducing AD symptoms and especially 2:1 blending oil were most effective. There were statistically significant differences by the three treatment periods in all dependent variables (p<.001). There were statistically significant interactions between oil types and treatment periods in all dependent variables (p<.01). For decreasing superoxide radical, degranulated mast cells, and epidermal thickness, 2:1 mixed oil should be applied for at least 21 days. Otherwise to reduce IgE, 2:1 mixed oil should be used for at least 7 days.

CONCLUSION

These findings provide bases for developing effective interventions for AD patients to manage their AD symptoms.

Shark cartilage extract induces cytokines expression and release in endothelial cells and induces E-selectin, plasminogen and t-PA genes expression through an antioxidant-sensitive mechanism

Neovastat® is a standardized extract of marine cartilage, an avascular tissue, which contains many biologically active molecules and has multiple antiangiogenic properties. In addition to VEGFR2 and MMPs inhibition, shark cartilage extract (SCE) has recently been shown to induce tissue plasminogen activator gene (PLAT) expression in bovine endothelial cells in a TNF like manner, by inducing the typical mediators NF-κB and JNK. There is now compelling evidences that the NF-κB and JNK pathways are activated by cytokines induced generation of reactive oxygen species (ROS). We used macroarray genes expression analysis on human umbilical vein endothelial cells, to investigate if that mechanism could mediate the effect of SCE. Transcriptomic results showed that SCE induced expression of several cytokines. Their impact must be important, given that treatment of endothelial cells with the cytokine TNF-α was able to reproduce most of the effects of cartilage extract on genes expression. In addition, most of the genes, known to be inducible by NF-κB or JNK following cytokines stimulation, were less induced by SCE when endothelial cells were pretreated with the antioxidant N-Acetylcysteine (NAC), suggesting a role of ROS in endothelial cell activation by SCE. Finally, the possible effects of PLAT, PLG, SELE, IL8 and PRDX2 (those validated by q-PCR) on angiogenesis, will also be discussed.

Reverse D4F, an apolipoprotein-AI mimetic peptide, inhibits atherosclerosis in ApoE-null mice

OBJECTIVE

Synthetic class A amphipathic helical peptide analogs of apolipoprotein-AI (apoAI; with varied phenylalanine residues) are emerging therapeutic approaches under investigation for atherosclerosis. Utilizing retroinverso sequencing, we designed reverse-D4F (Rev-D4F) peptide with 18 d-amino acids containing 4 phenylalanine residues and reverse order that allows the side chain residues to be of exact alignment and superimposable to those of the parent l-amino acid peptide. This study examined the effect of Rev-D4F on atherosclerosis in apolipoprotein E (apoE)-null mice and the underlying mechanisms.

MATERIALS/METHODS

ApoE-null mice were fed a chow diet and administered water (control), Rev-D4F, or L4F mimetic peptides (0.4 mg/mL, equivalent to 1.6 mg/d) orally in drinking water for 6 weeks. Aortic root atherosclerotic lesion area, lesion macrophage content, and the ability of plasma high-density lipoprotein (HDL) to influence monocyte chemotaxis were measured.

RESULTS

Rev-D4F significantly decreased aortic sinus atherosclerotic lesion area and lesion macrophage content without affecting plasma total and HDL-cholesterol levels in apoE-null mice. The HDL from Rev-D4F-treated mice showed enhanced anti-inflammatory monocyte chemotactic activity, while low-density lipoprotein (LDL) exhibited reduced proinflammatory activity. In in vitro studies, Rev-D4F inhibited LDL oxidation, endothelial cell vascular cell adhesion molecule 1 (VCAM-1), and monocyte chemotactic factor 1 (MCP-1) expression, and monocyte adhesion to aortic endothelial cells.

CONCLUSIONS

The Rev-D4F inhibits atherosclerosis by inhibiting endothelial inflammatory/oxidative events and improving HDL function. The data suggest that Rev-D4F may be an effective apoAI mimetic peptide for further development in preventing atherosclerosis.

Effects of erythropoietin on ICAM-1 and PECAM-1 expressions on human umbilical vein endothelial cells subjected to oxidative stress

The protective effect of erythropoietin (Epo) is based on its ability to reduce oxidation and to stabilize the cells. The aim of the study was to evaluate the influence of Epo on malonyl dialdehyde (MDA), intercellular adhesion molecule-1 (ICAM-1) (CD54) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) (CD31) levels on human umbilical vein endothelial cells (HUVECs) stimulated by tumour necrosis factor-α (TNF-α). HUVECs were incubated with Epo (10-40 IU ml⁻¹) or TNF-α (10-40 ng ml⁻¹) alone or preincubated with Epo (20 IU ml⁻¹) and subsequently stimulated with TNF-α (10-40 ng ml⁻¹). MDA concentrations were measured using the high-performance liquid chromatography, whereas ICAM-1 and PECAM-1 expressions were evaluated by flow cytometry. Incubation with Epo resulted in a decrease in MDA and the increased expressions of ICAM-1 and PECAM-1. Exposure to TNF-α reflected an increase in MDA, ICAM-1 and PECAM-1 levels. These changes were inhibited by preincubation with Epo. The cytoprotective activity proven in this study points to new applications and therapeutic possibilities for Epo.

Rb1 postconditioning attenuates liver warm ischemia-reperfusion injury through ROS-NO-HIF pathway

AIMS

Ginsenoside Rb1 could prevent ischemic neuronal death and focal cerebral ischemia, but its roles to liver warm I/R injury remain to be defined. We determined if Rb1 would attenuate warm I/R injury in mice.

MAIN METHODS

Mice were divided into sham, I/R, Rb1+I/R (Rb1 postconditioning, 20mg/kg, i.p. after ischemia), sham+L-NAME, I/R+L-NAME, and Rb1+I/R+L-NAME groups using 60min of the liver median and left lateral lobes ischemia. Serum levels of alanine aminotransferase (ALT) were measured and morphology changes of livers were evaluated. Contents of nitric oxide (NO) and nitric oxide synthase (NOS), malondialdehye (MDA) and activity of superoxide dismutase (SOD) were measured. Expressions of Akt, p-Akt, iNOS, HIF-1alpha, tumor necrosis factor-a (TNF-α) and intercellular adhesion molecule-1 (ICAM-1) were also determined by western blot or immunohistochemistry.

KEY FINDINGS

Rb1 postconditioning attenuated the dramatically functional and morphological injuries. The levels of ALT were significantly reduced in Rb1 group (p<0.05). Rb1 upregulated the concentrations of NO, iNOS in serum, iNOS, and activity of SOD in hepatic tissues (p<0.05), while it dramatically reduced the concentration of MDA (p<0.05). Protein expressions of p-Akt, iNOS and HIF-1alpha were markedly enhanced in Rb1 group. Protein and mRNA expressions of TNF-α and ICAM-1 were markedly suppressed by Rb1 (p<0.05).

SIGNIFICANCE

We found that Rb1 postconditioning could protect liver from I/R injury by upregulating the content of NO and NOS, and also HIF-1alpha protein expression. These protective effects could be abolished by L-NAME. These findings suggested Rb1 may have the therapeutic potential through ROS-NO-HIF pathway for management of liver warm I/R injury.

Hydrogen-rich saline improves memory function in a rat model of amyloid-beta-induced Alzheimer's disease by reduction of oxidative stress

This study is to examine if hydrogen-rich saline reduced amyloid beta (Abeta) induced neural inflammation, and learning and memory deficits in a rat model. S-D male rats (n=84, 280-330g) were divided into three groups, sham-operated, Abeta1-42 injected and Abeta1-42 plus hydrogen-rich saline-treated animals. Hydrogen-rich saline (5ml/kg, i.p., daily) was injected for 14days after intracerebroventricular injection of Abeta1-42. The levels of MDA, IL-6 and TNF-alpha were assessed by biochemical and ELISA analysis. Morris Water Maze and open field task were used to assess the memory dysfunction and motor dysfunction, respectively. LTP were used to detect the electrophysiology changes, HNE and GFAP immunohistochemistry were used to assess the oxidative stress and glial cell activation. After Abeta1-42 injection, the levels of MDA, IL-6, and TNF-alpha were increased in brain tissues and hydrogen-rich saline treatment suppressed MDA, IL-6, and TNF-alpha concentration. Hydrogen-rich saline treatment improved Morris Water Maze and enhanced LTP in hippocampus blocked by Abeta1-42. Furthermore, hydrogen-rich saline treatment also decreased the immunoreactivitiy of HNE and GFAP in hippocampus induced by Abeta1-42. In conclusion, hydrogen-rich saline prevented Abeta-induced neuroinflammation and oxidative stress, which may contribute to the improvement of memory dysfunction in this rat model.

Involvement of nitric oxide in acute lung inflammation induced by cigarette smoke in the mouse

Short-term exposure to cigarette smoke (CS) leads to acute lung inflammation (ALI) by disturbing oxidant/antioxidant balance. Both CS exposure and lung inflammation are important risk factors in the pathogenesis of chronic obstructive pulmonary disease. Nitric oxide (NO) is an oxidant both present in CS and produced in the inflammatory response, but its role in the effects of CS exposure is unclear. Our aim was to study involvement of NO in a model of CS exposure. Groups of mice (male C57BL/6) exposed to CS (six cigarettes per day over five days) were simultaneously subjected to treatment with vehicle (CS), 60mg/kg/day omega-nitro-l-arginine methyl ester (CS+l-NAME), 20mg/kg/day nitroglycerine (CS+NTG), or 120mg/kg/day l-arginine (CS+l-arg). Bronchoalveolar lavage fluid was then aspirated to perform cell counts, and malondialdehyde (MDA), nitrite, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels were measured in lung homogenates. Macrophage and neutrophil counts were increased in the CS (p<0.001) and CS+l-NAME groups (p<0.05 and p<0.01, respectively); the CS+NTG and CS+l-arg groups showed no differences from the control group. MDA was increased in the CS (p<0.05) and CS+l-NAME (p<0.01) groups when compared to the control group. Nitrite levels were decreased in the CS and CS+l-NAME groups (p<0.001) and increased in the CS+NTG (p<0.001) and CS+l-arg (p<0.01) groups when compared to the control. CAT, SOD and GPx activities in the CS and CS+l-NAME groups were all significantly increased compared to the control group. Our results suggest that administration of NO donors or substrates may be a useful therapy in the treatment of ALI caused by CS.

NF-kappaB, but not p38 MAP kinase, is required for TNF-alpha-induced expression of cell adhesion molecules in endothelial cells

In response to inflammation stimuli, tumor necrosis factor-alpha (TNF-alpha) induces expression of cell adhesion molecules (CAMs) in endothelial cells (ECs). Studies have suggested that the nuclear factor-kappaB (NF-kappaB) and the p38 MAP kinase (p38) signaling pathways play central roles in this process, but conflicting results have been reported. The objective of this study is to determine the relative contributions of the two pathways to the effect of TNF-alpha. Our initial data indicated that blockade of p38 activity by chemical inhibitor SB203580 (SB) at 10 microM moderately inhibited TNF-alpha-induced expression of three types of CAMs; ICAM-1, VCAM-1 and E-selectin, indicating that p38 may be involved in the process. However, subsequent analysis revealed that neither 1 microM SB that could completely inhibit p38 nor specific knockdown of p38alpha and p38beta with small interference RNA (siRNA) had an apparent effect, indicating that p38 activity is not essential for TNF-alpha-induced CAMs. The most definitive evidence to support this conclusion was from the experiments using cells differentiated from p38alpha knockout embryonic stem cells. We could show that deletion of p38alpha gene did not affect TNF-alpha-induced ICAM-1 and VCAM-1 expression when compared with wild-type cells. We further demonstrated that inhibition of NF-kappaB completely blocked TNF-alpha-induced expression of ICAM-1, VCAM-1 and E-selectin. Taken together, our results clearly demonstrate that NF-kappaB, but not p38, is critical for TNF-alpha-induced CAM expression. The inhibition of SB at 10 microM on TNF-alpha-induced ICAM-1, VCAM-1 and E-selectin is likely due to the nonspecific effect of SB.

Human squamous cell carcinomas evade the immune response by down-regulation of vascular E-selectin and recruitment of regulatory T cells

Squamous cell carcinomas (SCCs) of the skin are sun-induced skin cancers that are particularly numerous in patients on T cell immunosuppression. We found that blood vessels in SCCs did not express E-selectin, and tumors contained few cutaneous lymphocyte antigen (CLA)(+) T cells, the cell type thought to provide cutaneous immunosurveillance. Tumors treated with the Toll-like receptor (TLR)7 agonist imiquimod before excision showed induction of E-selectin on tumor vessels, recruitment of CLA(+) CD8(+) T cells, and histological evidence of tumor regression. SCCs treated in vitro with imiquimod also expressed vascular E-selectin. Approximately 50% of the T cells infiltrating untreated SCCs were FOXP3(+) regulatory T (T reg) cells. Imiquimod-treated tumors contained a decreased percentage of T reg cells, and these cells produced less FOXP3, interleukin (IL)-10, and transforming growth factor (TGF)-beta. Treatment of T reg cells in vitro with imiquimod inhibited their suppressive activity and reduced FOXP3, CD39, CD73, IL-10, and TGF-beta by indirect mechanisms. In vivo and in vitro treatment with imiquimod also induced IL-6 production by effector T cells. In summary, we find that SCCs evade the immune response at least in part by down-regulating vascular E-selectin and recruiting T reg cells. TLR7 agonists neutralized both of these strategies, supporting their use in SCCs and other tumors with similar immune defects.

Niacin inhibits vascular oxidative stress, redox-sensitive genes, and monocyte adhesion to human aortic endothelial cells

In pharmacological doses, nicotinic acid (niacin) reduces myocardial infarction, stroke and atherosclerosis. The beneficial effects of niacin on lipoproteins are thought to mediate these effects. We hypothesized that niacin inhibits oxidative stress and redox-sensitive inflammatory genes that play a critical role in early atherogenesis. In cultured human aortic endothelial cells (HAEC), niacin increased nicotinamide adenine dinucleotide phosphate (NAD(P)H) levels by 54% and reduced glutathione (GSH) by 98%. Niacin inhibited: (a) angiotensin II (ANG II)-induced reactive oxygen species (ROS) production by 24-86%, (b) low density lipoprotein (LDL) oxidation by 60%, (c) tumor necrosis factor alpha (TNF-alpha)-induced NF-kappaB activation by 46%, vascular cell adhesion molecule-1 (VCAM-1) by 77-93%, monocyte chemotactic protein-1 (MCP-1) secretion by 34-124%, and (d) in a functional assay TNF-alpha-induced monocyte adhesion to HAEC (41-54%). These findings indicate for the first time that niacin inhibits vascular inflammation by decreasing endothelial ROS production and subsequent LDL oxidation and inflammatory cytokine production, key events involved in atherogenesis. Initial data presented herein support the novel concept that niacin has vascular anti-inflammatory and potentially anti-atherosclerotic properties independent of its effects on lipid regulation.

A study on the action of vitamin E supplementation on plasminogen activator inhibitor type 1 and platelet nitric oxide production in type 2 diabetic patients

BACKGROUND AND AIM

Type 2 diabetic (T2DM) patients show decreased fibrinolysis, mainly linked to high plasminogen activator inhibitor type 1 (PAI-1) production, together with a reduced bioavailability of nitric oxide and an impairment in Na(+)/K(+)-ATPase activity possibly involved in increased cardiovascular risk. Vitamin E is the major natural lipid-soluble antioxidant in human plasma. The present work was conducted in order to measure PAI-1, ICAM and VCAM-1 plasma levels, platelet nitric oxide production and membrane Na(+)/K(+)-ATPase activity in type 2 diabetic subjects treated with vitamin E (500 IU/day) for 10 weeks and then followed for other 20 weeks.

METHODS AND RESULTS

Thirty-seven T2DM patients (24 males and 13 females) were studied. None of them were affected by any other disease or diabetic complications. Significant differences were detected for PAI-1 antigen (p<0.001), PAI-1 activity (p<0.001), nitric oxide (NO) production (p<0.001), and Na(+)/K(+)-ATPase activity (p<0.001) among the 4 phases of the study. A significant decrease both in ICAM and VCAM-1 plasma levels was also found at the 10th week compared with baseline (respectively p<0.001 and p<0.05).

CONCLUSION

Our data suggest that vitamin E counteracts endothelial activation in T2DM patients possibly representing a new tool for endothelial protection.

The causes of the Charcot syndrome

The Charcot syndrome is a rare complication of neuropathy in diabetes and is characterized by an acute inflammatory episode of the foot that is associated with variable degrees of dislocation, fracture, and deformity. It has no single cause but represents the final common pathway in people who are predisposed to its development by the varying overlap of several different factors. The association of the active phase of the disease with inflammation, increasing osteopenia, and increasing calcification of the arterial walls strongly suggests, however, the involvement of the receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin (OPG) cytokine pathway, which is closely involved in all three processes. The evidence for increased expression of RANKL and OPG in diabetes and neuropathy as well as its potential significance is reviewed.

Microvascular and C-fiber function in diabetic charcot neuroarthropathy and diabetic peripheral neuropathy

OBJECTIVE

Sympathetic denervation and hyperemia are implicated in the pathogenesis of Charcot neuroarthropathy (CN) but are also features of diabetic peripheral neuropathy (DPN). Differences in these physiological parameters were sought by determining C-fiber function (laser Doppler imager [LDI]flare technique) and maximum microvascular hyperemia (MMH) in 13 subjects with diabetic CN (DCN), 10 subjects with DPN, and 10 healthy control subjects. Additionally, unaffected limbs of the nine DCN subjects with unilateral CN (UCN) were studied to determine whether any observed differences precede CN.

RESULTS

LDIflare area was reduced in DPN (mean +/- SD 1.41 +/- 0.51 cm(2)) and DCN (1.42 +/- 0.37) groups compared with the healthy control group (5.24 +/- 1.33; P < 0.0001). MMH was higher in DCN (432 +/- 88 PU [perfusion units]) than in DPN (262 +/- 71; P = 0.001) subjects but lower than in the control group (564 +/- 112; P < 0.01). LDIflare area and MMH were similar in the UCN and DCN groups.

CONCLUSIONS

C-fiber function is equally impaired in neuropathic patients with and without CN; however, a higher MMH distinguishes those with CN. Unaffected and affected limbs of those with unilateral CN have the same neurovascular abnormalities, suggesting that these abnormalities precede CN and are not a result of CN.

Nitric oxide and metastatic cell behaviour

Nitric oxide (NO) is a pleiotropic signalling molecule that subserves a wide variety of basic cellular functions and also manifests itself pathophysiologically. As regards cancer and its progression, however, the reported role of NO appears surprisingly inconsistent. In this review, we focus on metastasis, the process of cancer cell spread and secondary tumour formation. In a 'reductionist' approach, we consider the metastatic cascade to be made up of a series of basic cellular behaviours (such as proliferation, apoptosis, adhesion, secretion migration, invasion and angiogenesis). We evaluate how NO controls such behaviours, in comparison with normal cells. The available information suggests strongly that NO signalling would be expected to regulate these behaviours both positively and negatively and this probably leads to the observed apparent variability in the NO status of cancer cells and tissues. Thus, the role of NO in cancer is more complex than previously thought. A number of suggestions are made, including consideration of novel mechanisms, such as ion channels, in order to achieve a more consistent and integrated understanding of NO signalling in cancer and to realise its clinical potential.

The role of proinflammatory cytokines in the cause of neuropathic osteoarthropathy (acute Charcot foot) in diabetes

The pathogenesis of the acute Charcot foot of diabetes remains unclear. All patients with this condition have evidence of peripheral neuropathy, with loss of protective sensation and abnormal foot biomechanics. However, the acute Charcot foot is also characterised by a pronounced inflammatory reaction and the pathogenic significance of this inflammation has received little attention. We suggest that an initial insult--which may or may not be detected--is sufficient to trigger an inflammatory cascade through increased expression of proinflammatory cytokines, including TNFalpha and interleukin 1beta. This cascade then leads to increased expression of the nuclear transcription factor, NF-kappaB, which results in increased osteoclastogenesis. Osteoclasts cause progressive bone lysis, leading to further fracture, which in turn potentiates the inflammatory process. The potential role of proinflammatory cytokines suggests the possibility of new treatments for this sometimes devastating complication of diabetes.

Abnormalities of vasomotor regulation in the pathogenesis of the acute charcot foot of diabetes mellitus

The acute Charcot foot complicates distal symmetrical neuropathy but is remarkably rare. This article reviews the multiple processes that may complicate both diabetes and neuropathy and might, in turn, explain the association of features that are typical of this disorder: osteolysis, vascular calcification in association with intact lower limb blood flow, and uncontrolled inflammation. Specifically, it is suggested that the disorder arises because of abnormal expression of the nuclear transcription factor, NFkappaB, in diabetic neuropathy and that this is further enhanced at the onset of the acute arthropathy as a result of the release of proinflammatory cytokines, such as tumor necrosis factor-alpha and interleukin-1. These proinflammatory cytokines and RANKL may then enter a cycle of mutual augmentation, and this is a factor that underlies the continuing inflammation that characterizes the disorder. If this hypothesis is confirmed, it would suggest the option of new effective treatments for this sometimes devastating disorder.

Human microvascular endothelial cells from different fetal organs demonstrate organ-specific CAM expression

In this work, we isolated and produced long-term cultures of human fetal endothelial cells (fECs) deriving from different organs of the same 12-week-old embryos. Highly pure endothelium cultures were obtained from specimens of brain, heart, lung, liver, aorta and kidney by using magnetic microspheres coated with CD31 or CD34 specific endothelial antibodies. The endothelial nature of these cells was confirmed by the presence of von Willebrand Factor (vWf), Flk-1/VEGFR2 and CD31. The fECs cultures showed organ-specific differences as regards to the morphological appearance, the growth rate and the expression of cellular adhesion molecules (CAMs) before or after stimulation by the inflammatory cytokines IL-1beta and TNF-alpha. For instance, TNF-alpha showed a specific effect on fetal heart ECs by stimulating E-selectin expression. Our findings indicate that fECs may represent an innovative tool to study differences among ECs of different vascular districts of the same individual, thus increasing the possibility to compare many pathological aspects of human adult and fetal microvasculature.

HUVECs from newborns with a strong family history of myocardial infarction overexpress adhesion molecules and react abnormally to stimulating agents

Atherosclerosis is a complex disease involved in major fatal events such as myocardial infarction and stroke. It is the result of interactions between metabolic, dietetic and environmental risk factors acting on a genetic background that could result in endothelial susceptibility. Our aim was to determine the patterns of expression of adhesion molecules and whether phosphatidylserine is translocated to the cell surface of human umbilical vein endothelial cells (HUVECs) isolated from healthy newborns born to parents with a strong family history of myocardial infarction under TNF-alpha or oxLDL stimulated conditions. Compared to control HUVECs, experimental cords showed: (a) a four-fold increase in VCAM-1 expression under basal conditions, which showed no change after stimulation with the pro-atherogenic factors; (b) a two-fold increase in basal P-selectin expression that reached a 10-fold increase with any of the pro-atherogenic factors; (c) a basal ICAM-1 expression similar to P-selectin that was not modified by the pro-atherogenic molecules; (d) a similar PECAM-1 expression. Unexpectedly, phospathidylserine expression in experimental cord HUVECs was significantly increased (211 817 versus 3354 TFU) but was not associated to apoptotic death as the percentage of dead cells induced by TNF-alpha treatment was very low (0.55 versus 9.87% in control HUVECs). The latter result was corroborated by TUNEL staining. T cell adherence to HUVECs was highly up-regulated in the genetically predisposed samples. The analysis of nonpooled HUVECs, from newborns to family predisposed myocardial-infarction individuals, might represent a useful strategy to identify phenotypical and functional alterations, and hopefully, to take early preventive actions.

ONO-1078 reduces NMDA-induced brain injury and vascular cell adhesion molecule-1 expression in rats

AIM

To determine whether ONO-1078 (pranlukast), a potent cysteinyl leukotriene receptor 1 (CysLT1) antagonist, has an effect on N-methyl-D-aspartate (NMDA)-induced brain injury and vascular cell adhesion molecule-1 (VCAM-1) expression in rats.

METHODS

Brain injury was induced by direct microinjection of NMDA (0.3 mumol in 1 muL of sterile 0.1 mol/L PBS, pH 7.4) into the cerebral cortex. The lesion volume (area), brain edema and neuron density were assessed by an image analyzer and the expression of VCAM-1 in the cortex was detected by Western blot 24 h after NMDA injection. ONO-1078 (0.03, 0.1, or 0.3 mg/kg) and edaravone (MCI-186, 10 mg/kg), a neuroprotective agent, were ip injected 30 min before and after NMDA injection.

RESULTS

NMDA microinjection produced well-defined focal lesions dose- and time-dependently. ONO-1078 (0.1, 0.3 mg/kg) and edaravone (10 mg/kg) decreased the total lesion volume, lesion area and brain edema induced by NMDA. Furthermore, ONO-1078 (0.1, 0.3 mg/kg) significantly inhibited the enhanced expression of VCAM-1 in the injured cortices, but edaravone did not have this effect.

CONCLUSION

CysLT1 receptor antagonist ONO-1078 attenuates NMDA-induced brain damage in rats, and this might relate to the attenuation of NMDA receptor-dependent neurotoxicity and the inhibition of the upregulation of VCAM-1 expression.

Differential gene expression in pulmonary artery endothelial cells exposed to sickle cell plasma

Clinical variability in sickle cell disease (SCD) suggests a role for extra-erythrocytic factors in the pathogenesis of vasoocclusion. We hypothesized that endothelial cell (EC) dysfunction, one possible modifier of disease variability, results from induction of phenotypic changes by circulating factors. Accordingly, we analyzed gene expression in cultured human pulmonary artery ECs (HPAEC) exposed to plasma from 1) sickle acute chest syndrome (ACS) patients, 2) SCD patients at steady state, 3) normal volunteers, and 4) serum-free media, using whole genome microarrays (U133A-B GeneChip, Affymetrix). Data were analyzed by Bayesian analysis of differential gene expression (BADGE). Differential expression was defined by the probability of >1.5 fold change in signal intensity greater than 0.999 and a predicted score of 70-100, measured by cross-validation. Compared with normal plasma, plasma from SCD patients (steady state) resulted in differential expression of 50 genes in HPAEC. Of these genes, molecules involved in cholesterol biosynthesis and lipid transport, the cellular stress response, and extracellular matrix proteins were most prominent. Another 58 genes were differentially expressed in HPAEC exposed to plasma from ACS patients. The pattern of altered gene expression suggests that plasma from SCD patients induces an EC phenotype which is anti-apoptotic and favors cholesterol biosynthesis. An altered EC phenotype elicited by SCD plasma may contribute to the pathogenesis of sickle vasoocclusion.

Nitric oxide in wound-healing

Modulation of the complex process of wound-healing remains a surgical challenge. Little improvement beyond controlling infection, gentle tissue handling, and debridement of necrotic tissue has been had in the modern era. However, increasing appreciation of the process from a biomolecular perspective offers the potential for making significant strides in wound modulation. The bioactive molecule nitric oxide was found to have wide-ranging impact on cellular activities, including the cellular responses engendered by wound healing. Current research suggests that nitric oxide and several nitric oxide donors can exert biologic effects, although the particular net responses of cells contributing to wound repair are context-dependent.

L-gamma-Glutamyl-L-cysteinyl-glycine (glutathione; GSH) and GSH-related enzymes in the regulation of pro- and anti-inflammatory cytokines: a signaling transcriptional scenario for redox(y) immunologic sensor(s)?

Of the antioxidant/prooxidant mechanisms mediating the regulation of inflammatory mediators, particularly cytokines, oxidative stress-related pathways remain a cornerstone. It is conspicuous that there is a strong association between free radical accumulation (ROS/RNS; oxidative stress) and the evolution of inflammation and inflammatory-related responses. The scenario that upholds a consensus on the aforementioned is still evolving to unravel, from an immunologic perspective, the molecular mechanisms associated with ROS/RNS-dependent inflammation. Cytokines are keynote players when it comes to defining an intimate relationship among reduction-oxidation (redox) signals, oxidative stress and inflammation. How close we are to identifying the molecular basis of this intricate association should be weighed against the involvement of specific signaling molecules and, potentially, transcription factors. L-gamma-Glutamyl-L-cysteinyl-glycine, or glutathione (GSH), an antioxidant thiol, has shaped, and still is refining, the face of oxidative signaling in terms of regulating the milieu of inflammatory mediators, ostensibly via the modulation (expression/repression) of oxygen- and redox-responsive transcription factors, hence termed redox(y)-sensitive cofactors. When it comes to the arena of oxygen sensing, oxidative stress and inflammation, nuclear factor-kappaB (NF-kappaB) and hypoxia-inducible factor-1alpha (HIF-1alpha) are key players that determine antioxidant/prooxidant responses with oxidative challenge. It is the theme therein to underlie current understanding of the molecular association hanging between oxidative stress and the evolution of inflammation, walked through an elaborate discussion on the role of transcription factors and cofactors. Would that classify glutathione and other redox signaling cofactors as potential anti-inflammatory molecules emphatically remains of particular interest, especially in the light of identifying upstream and downstream molecular pathways for conceiving therapeutic, alleviating strategy for oxidant-mediated, inflammatory-related disease conditions.

Effects of antioxidants and NO on TNF-alpha-induced adhesion molecule expression in human pulmonary microvascular endothelial cells

Pro-inflammatory cytokines initiate the vascular inflammatory response via upregulation of adhesion molecules on the endothelium. Recent observations suggest that reactive oxygen intermediates may play a pivotal role in TNF-alpha signaling and upregulate gene expression. We therefore evaluated the effects of pyrrolidine dithiocarbamate (PDTC; 0.1 mM) and spermine NONOate (Sper-NO; 1 mM) on adhesion molecule expression and nuclear factor kappa B (NF-kappaB) activation induced by TNF-alpha (10 ng/ml) in cultured human pulmonary microvascular endothelial cells (PMVEC). Treatment of cells with TNF-alpha for 4 h significantly induced the surface expression of E-selectin and ICAM-1. Treatment with TNF-alpha for 8 h significantly induced the surface expression of E-selectin, ICAM-1 and VCAM-1. The upregulation of these adhesion molecules was suppressed significantly by pretreatment with PDTC or Sper-NO for 1 h. 8-Bromo-cyclic GMP (1 mM) had no such effect, suggesting that the NO donor's effect was non-cGMP-dependent. The mRNA expression of E-selectin, ICAM-1 and VCAM-1, and activation of NF-kappaB induced by TNF-alpha for 2 h were decreased significantly by the above two pretreatments. N-acetylcysteine (10 mM) and S-nitroso-N-acetylpenicillamine (1 mM) had little inhibitory effects on the cell surface and mRNA expression of these adhesion molecules stimulated by TNF-alpha. Treatment with TNF-alpha for 4 h enhanced HL-60 leukocyte adhesion to human PMVEC, the effect of which was inhibited significantly by pretreatment with PDTC or Sper-NO. These findings indicate that both cell surface and mRNA expression of adhesion molecules in human PMVEC induced by TNF-alpha are inhibited significantly by pretreatment with PDTC or Sper-NO, possibly in part through blocking the activation of NF-kappaB. Although our in vitro results cannot be directly extrapolated to the in vivo situation, they suggest a potential therapeutic approach for intervention in cytokine-mediated inflammatory processes in the human lung.