anti-iNOS Antibody Research Articles

Photobiomodulation effects on synovial morphology, iNOS gene, and protein expression in a model of acute inflammation.

To evaluate morphological aspects and inducible nitric oxide synthase (iNOS) gene and protein expression in a model of acute inflammation. Thirty-six female Wistar rats were assigned into three groups: control (saline, n = 12), sham (arthritis, n = 12), and PBM (arthritis and photobiomodulation, n = 12). Arthritis induction was performed with 200 μg of intra-articular Zymosan in sham and PBM animals. PBM was performed 24 h after induction with a laser device (λ = 808 nm, 25 mW of nominal power, fluence of 20 J/cm2, beam area of 0.02 mm2, time of 33 s, total energy of 0.825 J) with punctual and single dose application. Morphological analysis of joint structure (HE) and immunohistochemistry (anti-iNOS antibody) were performed on knee samples, and synovial tissue was submitted to RNA extraction, cDNA synthesis and gene expression analysis by quantitative polymerase chain reaction. Statistical analyses were performed with p < 0.05. It was observed an increase in the thickness of the synovial lining epithelium and inflammatory infiltrate in sham compared to PBM. Gene expression analysis showed higher iNOS expression in PBM, and iNOS protein expression decreased in PBM compared to sham. Photobiomodulation decreased inflammation in PBM animals, upregulated iNOS gene expression, however down egulated protein expression compared to sham.

Cynarin suppresses gouty arthritis induced by monosodium urate crystals

ABSTRACT The study is aimed to determine the effects of cynarin (Cyn) on mice with gouty arthritis (GA) induced by monosodium urate (MSU). We measured swelling in the hind paws of mice in vivo using Vernier calipers and ultrasound. The liver, kidney, and hind paws were stained with hematoxylin-eosin, and M1 type macrophages were detected in the hind paws using anti-F4/80 and anti-iNOS antibodies. The mRNA expression of inflammatory factors in bone marrow-derived macrophages (BMDMs) and in the hind paws was detected via quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasomes and the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways were analyzed via western blotting. Cyn was detected in vitro using Cell Counting Kit-8 (CCK-8). Cyn treatment reduced hind paw swelling and M1 macrophage infiltration, suppressed the mRNA expression of inflammatory factors, and inhibited NLRP3 inflammasome activation in vivo, in addition to inhibiting the phosphorylation of IKKa/β, p65, and c-Jun NH 2-terminal kinase (JNK). Furthermore, Cyn exerted anti-inflammatory and anti-swelling effects in mice with GA by regulating the NF-κB and JNK pathways and NLRP3 inflammasomes.

Prolonged Cold Ischemia and Indirect Alloimmunity Are Fundamental for the Development of Chronic Lung Allograft Dysfunction

<h3>Purpose</h3> Lung transplantation has the worst long-term survival in solid organ transplantation due to chronic lung allograft dysfunction (CLAD). Lymphatic vessels play central roles in alloimmunity by bridging innate and adaptive immune response. The purpose of this project is to study the role of lymphatic endothelium in CLAD development and to analyse the impact of prolonged donor cold ischemia on CLAD development in the experimental lung transplantation in mouse. <h3>Methods</h3> Single mismatch orthotopic left lung transplantation (left lungs from HLA-A2 knock-in mice on a C57BL/6J background or C57BL/6J as donor mice were orthotopically transplanted to C57BL/6J recipient mice) was used as a CLAD model. Donor lungs were induced to 4 hours cold ischemia at 4°C. CLAD development was analysed by Masson's trichrome staining. Lymphatic vessels were stained by anti-podoplanin and anti-LYVE-1 antibodies. Pro-inflammatory macrophages were stained by anti-iNOS antibody, anti-inflammatory macrophages were stained by anti-CD206 antibody. VEGFC source in macrophages were identified by dual immunofluorescence. <h3>Results</h3> Short cold allograft ischemia (1h, 4°C) resulted in the development of lymphocytic bronchiolitis (LB) 8 weeks after the surgery. Prolonged cold allograft ischemia resulted in the development of lymphocytic bronchiolitis (LB) already one week after the surgery and led to the late stage CLAD 8 weeks after reperfusion. All histological features of bronchiolitis obliterate syndrome and restrictive allograft syndrome (RAS) were observed in 8-weeks allogeneic lungs and were similar to human findings. The lungs from syngeneic recipients showed no pathological changes. In the allogeneic recipients, the lymphatic density increased during the CLAD development. VEGFC expression was observed in iNOS and CD206 positive macrophages. <h3>Conclusion</h3> Prolonged cold lung ischemia seems to facilitate the development of experimental late stage CLAD. Indirect alloimmunity and deteriorated ischemia-reperfusion injury are fundamental for the late stage CLAD development. Experimental allogeneic lung transplantation with prolonged cold ischemia leads to a lymphatic phenotype similar to human RAS. Proinflammatory and anti-inflammatory macrophages are likely to drive lymphangiogenesis by increased VEGFC expression.

Production of granulomas in Mycoplasma bovis infection associated with meningitis-meningoencephalitis, endocarditis, and pneumonia in cattle.

Mycoplasma bovis, the most important primary pathogen in the family Mycoplasmataceae, causes pneumonia, arthritis, otitis media, and mastitis in cattle. Histopathologic pulmonary changes associated with M. bovis infection have been characterized as suppurative-to-caseonecrotic bronchopneumonia; infection in other organs has been reported in only a few studies that examined caseonecrotic endocarditis and suppurative meningitis. Granulomatous lesions associated with M. bovis infection have been reported only rarely. We studied the granulomatous inflammation associated with M. bovis infection in several organs of 21 Japanese Black cattle. M. bovis was detected by isolation and loop-mediated isothermal amplification methods; other bacteria were detected using culture on 5% blood sheep agar and a MALDI-TOF MS Biotyper. Tissues were examined by histopathology and by immunohistochemistry (IHC) using anti-M. bovis, anti-Iba1, anti-iNOS, and anti-CD204 antibodies. All 21 cases, which included 2 cases of meningitis-meningoencephalitis, 8 cases of endocarditis, and 11 cases of bronchopneumonia, had caseonecrotic granulomatous inflammation associated with M. bovis infection. The IHC for macrophages revealed a predominance of iNOS-labeled (M1) macrophages in the inner layer of the caseonecrotic granulomas associated with meningitis-meningoencephalitis, endocarditis, and bronchopneumonia in Japanese Black cattle naturally infected with M. bovis.

The Clinical Significance of Tumor Associated Macrophages in Myelodysplastic Syndromes

Objective:The purpose of this study is to investigate the relationship between the infiltration of tumor associated macrophages (TAMs) and the disease risk stratification and survival of patients with myelodysplastic syndrome (MDS) and to explore the role of TAMs in the clinical prognosis.Methods:We retrospectively collected and analyzed 115 patients initially diagnosed wih myelodysplastic syndromes from January, 2010 to July, 2017 in West China Hospital of Sichuan University. Both bone marrow biopsy specimens and clinical data of the patients enrolled were collected. All patients were assessed prognosis by international prognostic scoring system (IPSS). We quantified the involvement of macrophage (MΦ), alternatively activated macrophage (M2 MΦ) and classic activated macrophage (M1 MΦ) in bone marrow specimen by staining with anti-CD68 monoclonal antibody, anti-CD163 monoclonal antibody, and anti-iNOS monoclonal antibody respectively. Log-rank test was used to evaluate the difference of overall survival (OS) among different subgroups. Logistic regression was used to evaluate the effect of clinical parameters on patients' OS. Cox proportional-hazards models were used to estimate the independent risk factors influencing the prognosis of patients.Results:1 In the high risk group of MDS, the composition of CD163+MΦ was higher than that of the low risk group(p < 0.001). In the low risk group of MDS, the composition of iNOS+ MΦ was higher than that of the group with high risk(p < 0.001).2 The median survival time and 3-year survival rate in the high CD163+MΦinfiltration group were significantly lower than those in the low infiltration group (13 months vs 43 months, 27% vs 64%, Log-rank test, P<0.001). The median survival time and 3-year survival rate in high iNOS+MΦ infiltration group were significantly higher than those in low infiltration group (42. 5 months vs 11 months, 65% vs 27% Log-rank test, P< 0.001).3 According to the infiltration degree of iNOS+MΦ and CD163+MΦ, the M1 (iNOShigh/CD 163low)and M2 TA(iNOSlow/CD163high) MΦ were further distinguished (The median OS were 53m and 15m respectively, p< 0.001).4 In multivariate analysis, high infiltration of CD163+MΦ and CD68+MΦ, low infiltration of iNOS+MΦ and low PLT level were independent risk factors for patients' OS .Conclusion and Discuss:The degree of bone marrow TAMs subtype infiltration in MDS patients was associated with disease risk group. CD163+M Φ was the main TAMs in the high risk group of MDS,while iNOS+M Φ was the main TAMs in the low risk group. There was a positive correlation between the infiltration of M1-TAMs and OS. On the contrary, there was a negative correlation between the infiltration of M2-TAMs and OS. Analyzing TAMs subsets in bone marrow of patients with MDS is helpful to evaluate disease risk and prognosis. DisclosuresNo relevant conflicts of interest to declare.

Establishment of novel meniscal scaffold structures using polyglycolic and poly-l-lactic acids.

The purpose of this study was to evaluate various types of meniscus scaffolds that mimic the meniscus structure, and to establish a novel cell-free meniscus scaffold with polyglycolic acid or poly-l-lactic acid. Four types of scaffolds were implanted into Japanese white rabbits: poly-l-lactic acid sponge poly-l-lactic acid, PGA-coated PLLA sponge, PGA lamination, and film-coated PGA lamination. Samples were harvested at 8 and 12 weeks after implantation, and a compression stress test was performed. The meniscus size and Ishida scores were evaluated for regenerated tissue. Immunohistochemistry was analyzed by anti-type I, II and X collagen antibodies to investigate the structure of the regenerated tissue, and by anti-iNOS antibody to investigate the inflammatory tissue of the meniscus. The cell nuclei of lymphocytes and foreign body multinucleated giant cells were counted in hematoxylin and eosin staining. Modified Mankin scores for cartilage degeneration were used for assessment after Safranin-O/Fast Green staining. The biomechanical test showed that l- and film-coated PGA lamination exhibited greater strength than s- and PGA-coated PLLA sponge. At 12 weeks, the size of meniscus and the Ishida score in implanted film-coated PGA lamination were improved significantly compared with the defect groups. The type II collagen staining intensity in the PGA lamination lamination is significantly higher than the defect at eight weeks. The staining intensity of iNOS and number of lymphocytes significantly increased in sponge poly-l-lactic acid at eight weeks, and increased in p-PLLA at 12 weeks. Foreign body multinucleated giant cells in implantation groups appeared, especially at eight weeks. The Mankin score for film-coated PGA lamination was significantly lower than for the defect at 12 weeks. Novel meniscal scaffolds especially PGA should possess not only biological but also biomechanical functions. In conclusions, film-coated PGA lamination was the beneficial property for meniscus scaffold from the points of better biomechanical function, good regeneration, and less inflammation with chondroprotective effects.

Modulation of Matrix Metalloproteinase 14, Tissue Inhibitor of Metalloproteinase 3, Tissue Inhibitor of Metalloproteinase 4, and Inducible Nitric Oxide Synthase in the Development of Periapical Lesions

IntroductionPeriapical cysts and granulomas are chronic lesions caused by an inflammatory immune response against microbial challenge in the root canal. Different cell types, cytokines, and molecules have been associated with periapical lesion formation and expansion. Therefore, because of the chronic inflammatory state of these lesions, the aim of this study was to evaluate the in situ expression of matrix metalloproteinase (MMP)-14 and -19, tissue inhibitor of metalloproteinase (TIMP)-3 and -4, CD68, and inducible nitric oxide synthase (iNOS) in periapical cysts and granulomas. MethodsSixteen cases of periapical cysts and 15 cases of periapical granulomas were analyzed. Ten normal dental pulps were used as the negative control. Immunohistochemistry was performed with anti–MMP-19, anti–MMP-14, anti–TIMP-3, anti–TIMP-4, anti-iNOS, and anti-CD68 antibodies. ResultsThe expression of TIMP-3, TIMP-4, iNOS, and CD68 was significantly higher in both the cyst and granuloma groups than in the control group. TIMP-4 was also significantly higher in cases of chronic apical abscess. There was also a significant difference in the expression of MMP-14 between the cyst and control groups. However, there were no differences in the expression of MMP-19 between the 3 groups. ConclusionsOur data suggest that the expression of MMP-14, TIMP-3, and TIMP-4 is associated with the development of periapical lesions.

The Role of Tumor Associated Macrophages in Multiple Myeloma and Its Pathophysiological Effect on Myeloma Cells Survival, Apopotosis and Angiogenesis

Abstract Objective The aim of this study is to explore the role of tumor associated macrophages (TAMs) in the prognosis, early treatment response of multiple myeloma and to investigate the role of TAMs on the proliferation, apoptosis£¬oncogene expression and chemotaxis of myeloma cells. Methods 1 In vivo we retrospectively collected and analyzed 240 patients initially diagnosed wih multiple myeloma and their bone marrow biopsy tissue from Jan, 2009 to June, 2014 in West China Hospital, Sichuan University, China. All the patients enrolled in this study were followed up till April, 2015. We observed and quantified the involvement of macrophage (M¦µ), classic activated macrophage (M1 M¦µ) and alternatively activated macrophage (M2 M¦µ) in bone marrow by immunohistochemical staining of anti-CD68 monoclonal antibody, anti-iNOS monoclonal antibody and anti-CD163 monoclonal antibody, respectively. We analyzed the relation between macrophage involvement with International Staging System (ISS) and the clinical response as well. The effect of different type macrophage involvement on prognosis, progression-free survival and overall survival were estimated. Time-to-event data were analyzed with the Kaplan-Meier method, and the differences were calculated using the Log-rank and Breslow tests. Cox proportional-hazards models were used to estimate hazard ratios and 95% confidence intervals for the main comparisons. 2 In vitro we induced human peripheral blood mononuclear cell£¨PBMC£© and human monocytic THP-1 cells to M2 macrophages with M-CSF or PMA in the presence of IL-4/13 in vitro. Macrophages were identified by morphology and flow cytometry. Two myeloma cell lines (RPMI 8226 and U266) were cocultured with M2 macrophages by using a transwell system. We measured myeloma cells proliferation through CCK-8 method and the pro-inflammatory cytokines expression (TNF-¦Á and IL-6) by ELISA. Real time PCR was applied to measure chemokines (CCL2 and CCL3), chemokine receptors (CCR2, CCR1, CCR5), vascular endothelial growth factor (VEGFA, VEGFB and VEGFC), VEGF receptors (VEGFR1-3), proto-oncogene serine/threonine-protein kinase Pim (PIM1-3). In addition, flow cytometry was used to analyze the apoptosis of myeloma cells induced by dexamethasone. Results 1 patients with high M2 macrophage involvement (&gt;40/hp) in bone marrow showed poorer response (including complete response and partial response after 3 cycles of chemotherapy) to Dexamethasone-containing regimen (23.9% versus 73%, P=5x10-13). On the contrary, the patients with high M1 macrophage involvement demonstrated much better response to regimen than low M1 macrophage (69.6 versus 40.6%, P=5x10-5). 2 Both progression-free survival and overall survival were significantly shorter with high M2 macrophage involvement than low involvement (median progression-free survival, 12.9 months vs. 39 months; hazard ratio for progression, 1.77, 95% confidence interval [CI], 1.14 to 2.74; P=0.01; and overall survival, 4.9 months vs. 59.2 months; hazard ratio for death, 2.63; 95% CI, 1.75 to 3.95; P&lt;0.001). 3 In vitro M2 macrophage stimulate myeloma cell proliferation. 4 In vitro M2 macrophage protect myeloma cells from dexamethasone induced apoptosis. 5 In vitro M2 macrophage promote myeloma cells secreting higher level of IL-6, TNF-¦Á and higher expression of CCL2, CCL3, CCR2, CCR5, VEGFA, VEGFR-1,-2, PIM-1, PIM-2 compared with the non-macrophage coculture system. Conclusion TAMs are associated with early clinical response and prognosis. Notably, M2 macrophages involvement has been shown strongly negatively associated with progression-free survival and overall survival. M2 macrophages promote myeloma cells proliferation and protect from apoptosis through a very complex mechanism involving pro-inflammatory cytokines IL-6 and TNF-¦Á, chemokines and related receptors such as CCL2, CCL3, CCR2 and CCR3, VEGF, VEGFR and PIM1, PIM2. Figure 1. Kaplan-Meier Analysis of PFS and OS in multiple myeloma patients in total Macrophage subgroups (A), M1 subgroups (B) and M2 subgroups(C). Figure 1. Kaplan-Meier Analysis of PFS and OS in multiple myeloma patients in total Macrophage subgroups (A), M1 subgroups (B) and M2 subgroups(C). Figure 2. Macrophages promote myeloma cells proliferation. Figure 2. Macrophages promote myeloma cells proliferation. Disclosures No relevant conflicts of interest to declare.

Expression of cellular components in granulomatous inflammatory response in Piaractus mesopotamicus model.

The present study aimed to describe and characterize the cellular components during the evolution of chronic granulomatous inflammation in the teleost fish pacus (P. mesopotamicus) induced by Bacillus Calmette-Guerin (BCG), using S-100, iNOS and cytokeratin antibodies. 50 fish (120±5.0 g) were anesthetized and 45 inoculated with 20 μL (40 mg/mL) (2.0 x 106 CFU/mg) and five inoculated with saline (0,65%) into muscle tissue in the laterodorsal region. To evaluate the inflammatory process, nine fish inoculated with BCG and one control were sampled in five periods: 3rd, 7th, 14th, 21st and 33rd days post-inoculation (DPI). Immunohistochemical examination showed that the marking with anti-S-100 protein and anti-iNOS antibodies was weak, with a diffuse pattern, between the third and seventh DPI. From the 14th to the 33rd day, the marking became stronger and marked the cytoplasm of the macrophages. Positivity for cytokeratin was initially observed in the 14th DPI, and the stronger immunostaining in the 33rd day, period in which the epithelioid cells were more evident and the granuloma was fully formed. Also after the 14th day, a certain degree of cellular organization was observed, due to the arrangement of the macrophages around the inoculated material, with little evidence of edema. The arrangement of the macrophages around the inoculum, the fibroblasts, the lymphocytes and, in most cases, the presence of melanomacrophages formed the granuloma and kept the inoculum isolated in the 33rd DPI. The present study suggested that the granulomatous experimental model using teleost fish P. mesopotamicus presented a similar response to those observed in mammals, confirming its importance for studies of chronic inflammatory reaction.

Nitric Oxide Synthase - Nitric Oxide Involvement in the Human Neutrophil Free Radical Generation: Role of iNOS and Rac2 Interaction

AbstractAbstract 1036 Aims:Previous reports from this lab demonstrated importance of nitric oxide (NO) in augmenting neutrophils (PMNs) free radical generation. To explore further, present study investigated interaction of nitric oxide synthase (NOS) with Rac2 in resting and PMA activated human PMNs, and also nitration and nitrosylation of BSA following phagocytosis of coated beads. Results:Rac2 and iNOS interaction was evident in the cytosolic fraction of resting cells, which was augmented significantly in the membrane fraction of PMA treated PMNs. Nitration/nitrosylation of BSA, implicated functional importance of iNOS, and interaction of NO with NADPH-oxidase (NOX) and myeloperoxidase (MPO) derived species, as it was reduced significantly by the inhibitors of NOX (VAS), MPO (ABAH) and iNOS (1400W). Moreover, studies to assess the molecular characteristics and sub-cellular distribution of iNOS using standard methodologies, demonstrated iNOS transcript (RT-PCR, Real time PCR) and protein (immunoprecipitation and WB) in PMNs. iNOS protein was distributed in the granules, mitochondria, cytosol, nucleus and plasma membrane (immuno-electron microscopy and confocal microscopy) of human PMNs.Molecular characteristics, sub-cellular distribution of iNOS and its interaction with Rac2 are herein shown for the first time in human neutrophils. This study also elucidates the functional importance of iNOS-Rac2 interaction and highlighted the role of iNOS in nitration and nitrosylation of BSA following phagocytosis. Conclusions:Altogether these results suggest the functional importance of iNOS-Rac2 interaction in the nitration and S-nitrosylation of phagocytosed pathogens. [Display omitted] Association of iNOS with Rac2 and its migration to the membrane in activated PMNs (A) Total cell lysate of human PMNs (1 × 108 cells) were immunoprecipitated (IP) with anti-Rac2 antibody and blotted with anti-iNOS (Lane 1) or anti-nNOS antibody (Lane 4). Lanes 2 and 5 – IP with rabbit IgG (negative control for anti-Rac2). iNOS recombinant protein (Lane 3) and rat brain homogenate protein (Lane 6) were used as positive controls for iNOS (130 kDa) and nNOS (160 kDa) respectively. Lanes 7 and 8 were immunoprecipitated (IP) with anti-Rac2 antibody and blotted with anti-Rac2. Inducible NOS and Rac2 interaction in the cytosol and membrane fractions of resting, PMA andNSC23766with PMA stimulated cells. Both cytosol and membrane fractions were immunoprecipitated (IP) with anti-Rac2 antibody and blotted with anti-Rac2 (B) and anti-iNOS (C). The data represent 5 independent experiments, and are presented as Mean ± SEM (For Rac2, *** p<0.001 for control cytosol vs membrane fraction in control PMNs, * p<0.01 for cytosol vs membrane fraction in PMA treated PMNs or cytosol vs membrane fraction in NSC23766 with PMA treated PMNs, @p<0.01 for PMA vs control in cytosolic fraction and @@p<0.01 for PMA vs control in membrane fraction or NSC23766 PMA vs control in membrane fraction). (For iNOS, *** p<0.01 for cytosol vs membrane fraction in control PMNs or cytosol vs membrane fraction in NSC23766 with PMA treated PMNs, * p<0.01 for cytosol vs membrane fraction in PMA treated PMNs @p<0.05 for PMA cytosolic vs control cytosolic fraction or in PMA membrane vs control membrane fraction). Disclosures:No relevant conflicts of interest to declare.

Bladder pain syndrome/interstitial cystitis ESSIC type 3C: High expression of inducible nitric oxide synthase in inflammatory cells

Objective. Bladder pain syndrome/interstitial cystitis (BPS/IC) includes a heterogeneous collection of underlying pathological conditions. Compared to the classic IC with a Hunner lesion, now denominated ESSIC type 3C, the non-Hunner type of BPS/IC appears different in a number of respects. In a previous study, measuring luminal nitric oxide (NO) in the bladder of patients with BPS/IC, it was reported that all patients with ESSIC type 3C had high levels of NO. The aim of the present study was to investigate the source of inducible nitric oxide synthase (iNOS) and thereby the cellular origin of NO production via iNOS. Material and methods. Immunohistochemistry, with two different anti-iNOS antibodies, was used to study10 patients with BPS/IC ESSIC type 3C who expressed high levels of intraluminal NO. These results were compared with four patients with non-Hunner BPS/IC. To substantiate further the involvement of iNOS in this condition, the protein expression of nitrotyrosine, a marker for iNOS activation, was also assessed. Results. On routine histopathology, the tissues of type 3C patients exhibited inflammatory infiltrates of varying intensity. Strong immunoreactivity for both iNOS and nitrotyrosine was noted within the urothelium but also within the inflammatory infiltrates in the lamina propria of these subjects. Conclusions. The findings of a clearly detectable protein expression of iNOS in both the urothelium and the inflammatory infiltrates in bladder biopsies from patients with BPS/IC ESSIC type 3C suggest that the production of NO, in this entity, may occur in different tissue compartments.

Liver-specific Inducible Nitric-oxide Synthase Expression Is Sufficient to Cause Hepatic Insulin Resistance and Mild Hyperglycemia in Mice

Inducible nitric-oxide synthase (iNOS), a major mediator of inflammation, plays an important role in obesity-induced insulin resistance. Inhibition of iNOS by gene disruption or pharmacological inhibitors reverses or ameliorates obesity-induced insulin resistance in skeletal muscle and liver in mice. It is unknown, however, whether increased expression of iNOS is sufficient to cause insulin resistance in vivo. To address this issue, we generated liver-specific iNOS transgenic (L-iNOS-Tg) mice, where expression of the transgene, iNOS, is regulated under mouse albumin promoter. L-iNOS-Tg mice exhibited mild hyperglycemia, hyperinsulinemia, insulin resistance, and impaired insulin-induced suppression of hepatic glucose output, as compared with wild type (WT) littermates. Insulin-stimulated phosphorylation of insulin receptor substrate-1 (IRS-1) and -2, and Akt was significantly attenuated in liver, but not in skeletal muscle, of L-iNOS-Tg mice relative to WT mice without changes in insulin receptor phosphorylation. Moreover, liver-specific iNOS expression abrogated insulin-stimulated phosphorylation of glycogen synthase kinase-3β, forkhead box O1, and mTOR (mammalian target of rapamycin), endogenous substrates of Akt, along with increased S-nitrosylation of Akt relative to WT mice. However, the expression of insulin receptor, IRS-1, IRS-2, Akt, glycogen synthase kinase-3β, forkhead box O1, protein-tyrosine phosphatase-1B, PTEN (phosphatase and tensin homolog), and p85 phosphatidylinositol 3-kinase was not altered by iNOS transgene. Hyperglycemia was associated with elevated glycogen phosphorylase activity and decreased glycogen synthase activity in the liver of L-iNOS-Tg mice, whereas phosphoenolpyruvate carboxykinase, glucose-6-phosphatase, and proliferator-activated receptor γ coactivator-1α expression were not altered. These results clearly indicate that selective expression of iNOS in liver causes hepatic insulin resistance along with deranged insulin signaling, leading to hyperglycemia and hyperinsulinemia. Our data highlight a critical role for iNOS in the development of hepatic insulin resistance and hyperglycemia.

Electropolymerized Self-Assembled Layer on Gold Nanoparticles: Detection of Inducible Nitric Oxide Synthase in Neuronal Cell Culture

Novel nanostructures of gold nanoparticle (AuNP) encapsulated-conductive polymer have been developed to study biosensor probe materials and utilized to detect the concentration of inducible nitric oxide synthase (iNOS). A 2,2':5',5″-terthiophene-3'-benzoic acid (TTBA) monomer was synthesized and self-assembled on gold nanoparticles (AuNPs). The size effects of the AuNPs and TTBA monomer film thickness on the electrode conductivity were examined. Anti-iNOS antibody was covalently bound on an encapsulated-AuNPs polymer layer with self-assembled TTBA. The immunocomplex formation between iNOS and anti-iNOS was directly observed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). This study looked at the applicability of the self-assembled TTBA layer where the results indicated an efficient electrochemical response toward iNOS. The calibration plot of the current response vs. iNOS concentration exhibited a linear relationship in the range of 0.001-0.02 μg/mL. The calibration sensitivity of iNOS was 59.4 ± 0.3 mV/μg mL(-1). The detection limit of iNOS was determined to be 0.20 ± 0.04 ng/mL based on five time measurements (95% confidence level, k = 3, n = 5). Further results show that AuNP-encapsulated conductive polymers are good nanostructured materials as biosensor probes and have a potential application in cell biosensors.

Tail regenerative capacity and iNOS immunolocalization in Xenopus laevis tadpoles

The morphology and the immuno-distribution of the inducible isoform of nitric oxide synthase (iNOS) have been examined in regenerating tails from differently aged Xenopus laevis larvae. By comparing stage-50 and stage-55/56 tadpoles, various morphological aspects and immunoreactivity to anti-iNOS antibody in terms of the number and duration of positive cells have been demonstrated in the regenerating buds. Unlike in stage-50 larvae, the extent of responses to tail amputation in older larvae is more dependent on the individual tadpole and a high percentage (70%-80%) of malformed tails has been seen. The findings indicate that the decline in the efficiency of Xenopus tail regeneration is driven by differences in the inflammatory responses and in the involvement of nitric oxide. This molecule is induced and required for normal tail regeneration, whereas in excess, it is probably associated with progressive loss in the regeneration capability.

Detection of inducible nitric oxide synthase using a suite of electrochemical, fluorescence, and surface plasmon resonance biosensors

A suite of biosensors for rapid detection of inducible nitric oxide synthase (iNOS) is described. First, a metal-enhanced electrochemical detection (MED) sensor, which relied on the redox properties of a silver monolayer, was developed. The linear detection range was between 8.64 × 10 −2 and 5.4 × 10 1 ng/ml with a detection limit of 1.69 × 10 −4 ng/ml. This method was compared with surface plasmon resonance (SPR) biosensors in which polyclonal mouse anti-iNOS was covalently immobilized onto a gold surface using an iNOS antigen. The linear detection range recorded was between 3.37 × 10 1 and 5.4 × 10 −2 ng/ml with a detection limit of 2 × 10 −3 ng/ml. Finally, an ultrasensitive portable capillary (UPAC) fluorescence immunosensor, in which a mouse anti-iNOS antibody was covalently immobilized onto the inner surface of a capillary and a rabbit anti-iNOS antibody was employed as the secondary antibody, was developed. The resulting signals were found to be directly proportional to iNOS concentrations between 1.52 × 10 −1 and 1.52 × 10 −2 ng/ml with a detection limit of 1.05 × 10 −3 ng/ml. These immunosensors exhibit low cross-reactivity toward potential interferents such as human serum albumin and ovalbumin. The SPR and UPAC biosensors were validated using simulated blood spiked with recombinant iNOS, resulting in recoveries of 85% and 88.5%, respectively. The research presented in this article could potentially provide new ways of detecting NO for diagnostic and biomarker purposes in medical research.

In vivo detection of inducible nitric oxide synthase in rodent gliomas

Increased iNOS expression is often found in brain tumors, such as gliomas. The goal of this study was to develop and assess a novel molecular MRI (mMRI) probe for in vivo detection of iNOS in rodent models for gliomas (intracerebral implantation of rat C6 or RG2 cells or ethyl nitrosourea-induced glioma). The probe we used incorporated a Gd-DTPA (gadolinium(III) complex of diethylenetriamine- N,N,N′ ,N″ ,N″-pentaacetate) backbone with albumin and biotin moieties and covalent binding of an anti-iNOS antibody (Ab) to albumin (anti-iNOS probe). We used mMRI with the anti-iNOS probe to detect in vivo iNOS levels in gliomas. Nonimmune normal rat IgG coupled to albumin–Gd-DTPA–biotin was used as a control nonspecific contrast agent. By targeting the biotin component of the anti-iNOS probe with streptavidin Cy3, fluorescence imaging confirmed the specificity of the probe for iNOS in glioma tissue. iNOS levels in glioma tumors were also confirmed via Western blots and immunohistochemistry. The presence of plasma membrane-associated iNOS in glioma cells was established by transmission electron microscopy and gold-labeled anti-iNOS Ab. The more aggressive RG2 glioma was not found to have higher levels of iNOS compared to C6. Differences in glioma vascularization and blood–brain barrier permeability between the C6 and the RG2 gliomas are discussed. In vivo assessment of iNOS levels associated with tumor development is quite feasible in heterogeneous tissues with mMRI.

MMP-2, MMP-9, and iNOS Expression in Human Dental Pulp Subjected to Orthodontic Traction

To test the hypothesis that some metalloproteinases (MMP-2, MMP-9) and inducible nitric oxide synthetase (iNOS) enzymes in dental pulp samples do not vary when subjected to orthodontic treatment. Human dental pulps were taken from male and female patients (N=10; age 10-14 years). A straight wire technique was used with nickel-titanium or steel archwires. The increase of pressure applied on teeth was gradual. Five patients were subjected to premolar extractions after 14 months of treatment and one after 24 months. Samples were Bouin-fixed, paraffin-embedded, and afterwards processed for immunohistochemistry using anti-MMP-2, anti-MMP-9, and anti-iNOS antibodies. A reduction of MMP-2, MMP-9, and iNOS expression occurred in treated samples. This became more evident with increased treatment time. The hypothesis is rejected. The reduction of expression of those proteins revealed a time-dependent relationship.

The effects of Gemcitabine and Vinorelbine on inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) distribution of MCF-7 breast cancer cells

Gemcitabine, which induces S-phase arrest, and Vinorelbine, which arrests microtubule organization, are two agents that have demonstrate preferred anti-tumor activity. Nitric oxide acts in diverse functions including anti-tumor and anti-pathogenic activities. In this study, we aimed to examine the distribution of immunoreactivities of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) in cells of the MCF-7 breast cancer cell line in response to treatment with Gemcitabine (G), Vinorelbine (V) and combination of Gemcitabine and Vinorelbine (G+V). The distributions of iNOS and eNOS were determined by using indirect immunoperoxidase or immunofluorescence methods and ELISA. Cells incubated with G, V and G+V for 24, 48 and 72 h were immunolabelled with anti-eNOS and anti-iNOS primary antibodies. Apoptosis was determined by TUNEL assay. A significant increase of eNOS immunolabelling on MCF-7 cells treated with G and G+V was observed. Apoptotic cells were also detected in G, V and G+V treated MCF-7 cells. The immunolabelling of iNOS was detected in all groups but this immunoreactivity was not different among the groups. In conclusion, while G treatment, induced S-phase arrest, triggered the NOS pathway after treatment of MCF-7 cells, V treatment, arrested microtubule organization and did not change the NOS pathway. Detection of increased eNOS immunolabelling and apoptosis after G treatment of MCF-7 cells could be important to the treatment of human breast cancer.

Oxidative Stress and Compartment of Gene Expression Determine Proatherosclerotic Effects of Inducible Nitric Oxide Synthase

Genetic and pharmacological inhibition of inducible nitric oxide synthase (iNOS) decreases atherosclerosis development. Potential proatherogenic effects of iNOS include iNOS mediated oxidative stress and iNOS expression in different cellular compartments. Lesional iNOS can potentially produce nitric oxide radicals (NO), superoxide radicals (O2(-)), or both; these radicals may then react to form peroxynitrite. Alternatively, O2(-) radicals from oxidases co-expressed with iNOS could react with NO to produce peroxynitrite. Therefore, the expression profiles of the genes that modulate the redox system in different iNOS-expressing cell compartments may determine the role of iNOS in atherosclerosis. We used apoE (apoE(-/-)) and apoE/iNOS double knockout (apoE(-/-)/ iNOS(-/-)) mice to assess vascular NO, O2(-), and peroxynitrite formation by electron spin resonance spectroscopy, high performance liquid chromatography, and 3-nitrotyrosine staining. The relevance of the iNOS expressing cell compartment was tested by bone marrow transplantation. We show that iNOS significantly contributes to vascular NO production and itself produces O2(-), leading to peroxynitrite formation in atherosclerotic lesions. Our bone marrow transplantation experiments show that bone marrow derived cells exclusively mediate the proatherosclerotic effects of iNOS in males, while both parenchymal and bone marrow derived iNOS equally contribute to atherosclerosis in females. Moreover, iNOS expression affects vascular remodeling. These findings establish for the first time that the proatherosclerotic effects of iNOS vary with sex in addition to the compartment of its expression.

Trypanosoma cruzi: parasite shed vesicles increase heart parasitism and generate an intense inflammatory response

Trypanosoma cruzi trypomastigotes continuously shed into the medium plasma membrane fragments sealed as vesicles enriched in glycoproteins of the gp85 and trans-sialidase (TS) superfamily and α-galactosyl-containing glycoconjugates. Injection of a vesicle fraction into BALB/c mice prior to T. cruzi infection led to 40% of deaths on the 16th day post-infection and 100% on day 20th whereas 20% of untreated animals survived for more than 30 days. The vesicle-treated animals developed severe heart pathology, with intense inflammatory reaction and higher number of amastigote nests. Analysis of the inflammatory infiltrates 15 days after infection showed predominance of TCD4 + lymphocytes and macrophages, but not of TCD8 + cells, as well as a decrease of areas labeled with anti-iNOS antibodies as compared to the control. Higher levels of IL-4 and IL-10 mRNAs were found in the hearts and higher IL-10 and lower NO levels in splenocytes of vesicles pretreated animals. Treatment of mice with neutralizing anti-IL-10 or anti-IL-4 antibodies precluded the effects of pre-inoculation of membrane vesicles on infection. These results indicate that T. cruzi shed membrane components increase tissue parasitism and inflammation by stimulation of IL-4 and IL-10 synthesis and thus may play a central role in the pathogenesis of Chagas’ disease acute phase.