Upregulation Of iNOS Expression Research Articles

ITreg cells-secreted IL10 alleviates lupus nephritis through inactivating lncRNA HAR1A transcription to suppress SMARCD1-mediated iNOS activation

Lupus nephritis (LN) is a highly prevalent complication of systemic lupus erythematosus (SLE). Long non-coding RNAs (lncRNAs) are essential modulators in multiple types of human diseases, including LN. In the current study, we searched on online GEO database to select out lncRNAs that were differentially expressed in blood samples of LN patients. Through further RT-qPCR analysis, we found that lncRNA Highly Accelerated Region 1 A (HAR1A) is most significantly upregulated in blood samples of LN patients. Functionally, we detected that overexpression of HAR1A could aggravate LPS-induced injury and inflammation. According to the results of bioinformatics analysis and mechanism experiments, we determined that HAR1A binds with miR-149-3p to upregulate SMARCD1 through competing endogenous RNA (ceRNA) mechanism. It has been proven that iNOS is an inflammation inducer. Here, we found that HAR1A/miR-149-3p/SMARCD1 upregulates iNOS expression through enhancing H3K27ac level in iNOS promoter. Previously, we proved that CD8+CD103+ iTreg cells could alleviate glomerular endothelial cell injury. Moreover, we demonstrated that CD8 + CD103+ iTreg cells-secreted IL-10 downregulated HAR1A expression by impeding NF-κB pathway activation. In conclusion, this study provides evidences revealing a novel molecular pathway blocked by CD8+CD103+ iTreg cells in LN.

Extraction and molecular characterisation of polysaccharides from Suaeda maritima for their immunomodulatory effects

In the present study, Suaeda maritima polysaccharides (SMPs) were identified, characterised and evaluated for their immune-modulating effects on RAW264.7 macrophages and the underlying biological processes. Two acidic polysaccharides (SMP-F1 and SMP-F2) were obtained via ion-exchange chromatography from the crude polysaccharide (SMP-C). The SMP-C and its fractions mainly contained carbohydrates, proteins and sulphates, in variable proportions. Glucose, mannose, galactose and arabinose were the primary monosaccharide units, accompanied by smaller amounts of rhamnose and xylose. The molecular weight (Mw) of the SMPs ranged from 76.2 × 103 to 245.0 × 103 g/mol. SMPs can significantly induce the production of NO by up-regulating iNOS expression. The results showed that SMPs could increase TNF-α, IL-6, IL-10 and IL-12 expression. In addition, SMP-F2 significantly boosts inflammatory reactions more than SMP-C or SMP-F1. Further study revealed that SMP-F2 was found to stimulate macrophage phagocytosis and the expression of CD11b, CD14, CD40 and TLR4. The major chains of the strongest immunostimulant, SMP-F2, were mainly 1,3-linked Manp, 1,4-linked Glcp and 1,4-linked Galp. The side chain of SMP-F2 was 1,3,6-linked Manp and 1,4,6-linked Galp, with terminals of arabinose, mannose and glucose. These findings show that SMPs, particularly SMP-F2, promote the ability to modulate immunological responses.

PPARγ regulates osteoarthritis chondrocytes apoptosis through caspase-3 dependent mitochondrial pathway

Osteoarthritis (OA) is the most prevalent form of arthritis, characterized by a complex pathogenesis. One of the key factors contributing to its development is the apoptosis of chondrocytes triggered by oxidative stress. Involvement of peroxisome proliferator-activated receptor gamma (PPARγ) has been reported in the regulation of oxidative stress. However, there remains unclear mechanisms that through which PPARγ influences the pathogenesis of OA. The present study aims to delve into the role of PPARγ in chondrocytes apoptosis induced by oxidative stress in the context of OA. Primary human chondrocytes, both relatively normal and OA, were isolated and cultured for the following study. Various assessments were performed, including measurements of cell proliferation, viability and cytotoxicity. Additionally, we examined cell apoptosis, levels of reactive oxygen species (ROS), nitric oxide (NO), mitochondrial membrane potential (MMP) and cytochrome C release. We also evaluated the expression of related genes and proteins, such as collagen type II (Col2a1), aggrecan, inducible nitric oxide synthase (iNOS), caspase-9, caspase-3 and PPARγ. Compared with relatively normal cartilage, the expression of PPARγ in OA cartilage was down-regulated. The proliferation of OA chondrocytes decreased, accompanied by an increase in the apoptosis rate. Down-regulation of PPARγ expression in OA chondrocytes coincided with an up-regulation of iNOS expression, leading to increased secretion of NO, endogenous ROS production, and decrease of MMP levels. Furthermore, we observed the release of cytochrome C, elevated caspase-9 and caspase-3 activities, and reduction of the components of extracellular matrix (ECM) Col2a1 and aggrecan. Accordingly, utilization of GW1929 (PPARγ Agonists) or Z-DEVD-FMK (caspase-3 inhibitor) can protect chondrocytes from mitochondrial-related apoptosis and alleviate the progression of OA. During the progression of OA, excessive oxidative stress in chondrocytes leads to apoptosis and ECM degradation. Activation of PPARγ can postpone OA by down-regulating caspase-3-dependent mitochondrial apoptosis pathway.

New models of Parkinson's like neuroinflammation in human microglia clone 3: Activation profiles induced by INF-γ plus high glucose and mitochondrial inhibitors.

Microglia activation and neuroinflammation have been extensively studied in murine models of neurodegenerative diseases; however, to overcome the genetic differences between species, a human cell model of microglia able to recapitulate the activation profiles described in patients is needed. Here we developed human models of Parkinson's like neuroinflammation by using the human microglia clone 3 (HMC3) cells, whose activation profile in response to classic inflammatory stimuli has been controversial and reported only at mRNA levels so far. In fact, we showed the increased expression of the pro-inflammatory markers iNOS, Caspase 1, IL-1β, in response to IFN-γ plus high glucose, a non-specific disease stimulus that emphasized the dynamic polarization and heterogenicity of the microglial population. More specifically, we demonstrated the polarization of HMC3 cells through the upregulation of iNOS expression and nitrite production in response to the Parkinson's like stimuli, 6-hydroxidopamine (6-OHDA) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), the latter depending on the NF-κB pathway. Furthermore, we identified inflammatory mediators that promote the pro-inflammatory activation of human microglia as function of different pathways that can simulate the phenotypic transition according to the stage of the pathology. In conclusion, we established and characterized different systems of HMC3 cells activation as in vitro models of Parkinson's like neuroinflammation.

Dynamic changes of inducible nitric oxide synthase expression in rat’s retina and its role on blood-retinal barrier injury after acute high intraocular pressure

To clarify the role of inducible nitric oxide synthase (iNOS) in blood-retinal barrier (BRB) injury after acute high intraocular pressure (IOP) in rats. Forty-two Sprague-Dawley (SD) rats were randomized into 7 groups [control (Cont), 3, 6, 12, 24, 48, and 72h, n=6]. Except Cont group, other groups' retina tissue was obtained at corresponding time points after a model of acute high IOP have been established in rats. The expression of iNOS and tight junction protein zonula occludens (ZO)-1 was detected by Western blotting. Evans blue (EB; 3% ) was injected into the great saphenous vein to detect the leakage of EB by spectrophotometer. Nine rats were divided into Cont, 6h, 12h groups, the expression of iNOS was localized by immunofluorescence. In order to verify the role of iNOS in the damage to BRB, thirty-six rats were randomly divided into 4 groups [Cont, Cont+inhibitor (Inh), 6h and 6h+Inh, n=9]. After treatment with the iNOS-specific inhibitor 1400W, the expression of iNOS and ZO-1 and the leakage of BRB were detected again. The immunofluorescence results showed that the expression of iNOS was observed in the Cont group and 6h group, but not in the 12h group. iNOS was mainly expressed in the retinal nerve fiber layer, ganglion cell layer and inner nuclear layer and that it did not colocalize with the retinal ganglion cell marker NeuN but was co-expressed with the vascular endothelial cell marker CD31. Western blotting showed that in the early period (3h, 6h) after acute high IOP, the expression of iNOS was upregulated, then the down-regulation of iNOS were tested in the follow-up timing spots. ZO-1 expression showed a continuous down-regulation after 6h. The quantitative results for EB showed that the amount of EB leakage began to increase at 3h after acute high IOP. At 6h, the leakage of EB was lower, but at 12h, the leakage of EB was highest, after which it gradually recovered but remained higher than that in the Cont group. The expression of iNOS was down-regulated after 1400W treatment. ZO-1 expression was not significantly changed in the Cont+Inh group and the 6h group, and significantly down-regulated in the 6h+Inh group, and the leakage of EB was significantly increased after 1400W treatment. These results suggest that the upregulation of iNOS expression in the early stage after acute high IOP may have a protective effect on BRB injury.

Doxycycline hyclate stimulates inducible nitric oxide synthase and arginase imbalance, potentiating inflammatory and oxidative lung damage in schistosomiasis

BackgroundWe investigated the relationship between inducible nitric oxide synthase (iNOS) and arginase pathways, cytokines, macrophages, oxidative damage and lung granulomatous inflammation in S. mansoni-infected and doxycycline-treated mice. MethodsSwiss mice were randomized in four groups: (i) uninfected, (ii) infected with S. mansoni, (iii) infected + 200 mg/kg praziquantel (Pzt), (iv) and (v) infected + 5 and 50 mg/kg doxycycline. Pzt (reference drug) was administered in a single dose and doxycycline for 60 days. ResultsS. mansoni-infection determined extensive lung inflammation, marked recruitment of M2 macrophages, cytokines (IL-4, IL-5, IFN-γ, TNF-α) upregulation, intense eosinophil peroxidase (EPO) levels, arginase expression and activity, reduced iNOS expression and nitric oxide (NO) production. The higher dose of doxycycline aggravated lung granulomatous inflammation, downregulating IL-4 levels and M2 macrophages recruitment, and upregulating iNOS expression, EPO, NO, IFN-γ, TNF-α, M1 macrophages, protein carbonyl and malondialdehyde tissue levels. The number and size of granulomas in doxycycline-treated animals was higher than untreated and Pzt-treated mice. Exudative/productive granulomas were predominant in untreated and doxycycline-treated animals, while fibrotic/involutive granulomas were more frequent in Pzt-treated mice. The reference treatment with Pzt attenuated all these parameters. ConclusionOur findings indicated that doxycycline aggravated lung granulomatous inflammation in a dose-dependent way. Although Th1 effectors are protective against several intracellular pathogens, effective schistosomicidal responses are dependent of the Th2 phenotype. Thus, doxycycline contributes to the worsening of lung granulomatous inflammation by potentiating eosinophils influx and downregulating Th2 effectors, reinforcing lipid and protein oxidative damage in chronic S. mansoni infection.

Immune-enhancing effects of postbiotic produced by Bacillus velezensis Kh2-2 isolated from Korea Foods

Postbiotics defined as soluble factors (products or metabolic byproducts) that are released after bacterial lysis or secreted by live bacteria, have attracted considerable attention because of their long shelf life, safety, and beneficial effects. In this study, we investigated the immune-enhancing activities of squid jeotgal (a traditional Korean fermented seafood)-derived Bacillus velezensis Kh2-2 (Kh2-2) postbiotics in vitro, ex vivo, and in vivo. Cell lysates of four Bacillus species were prepared by sonication. In particular, Kh2-2 lysates induced NO production by upregulating iNOS expression in RAW264.7 cells compared with the lysates of B. subtilis Kh2-1, B. vallismortis Kh8-3, and B. amyloliquefaciens Kh3-1. Furthermore, Kh2-2 lysates stimulated immune activation of macrophages by upregulating the NF-κB and MAPK signaling pathways and promoting immune-related cytokine secretion. In the ex vivo study, Kh2-2 lysates stimulated proliferation and polarized Th1 response by inducing the production of IL-2 and IFN-γ and inhibiting IL-10 expression in splenocytes. The in vivo immune-enhancing effects of Kh2-2 lysates and Kh2-2 were further evaluated using a cyclophosphamide (CTX)-induced immunosuppression mouse model. The results showed that oral administration of Kh2-2 lysates improved CTX-induced immunosuppression by enhancing innate and adaptive immunity, stimulating immune-related cytokine secretion, and modulating gut microbiota dysbiosis in mice. Thus, we concluded that Kh2-2 lysates have potential as a functional material for postbiotics with immune-enhancing effects.

C-Terminal Fragment of Vitellogenin II, a Potential Yolkin Polypeptide Complex Precursor Protein-Heterologous Expression, Purification, and Immunoregulatory Activity.

The aim of this research was to analyze the heterologous expression, purification, and immunoregulatory activity of recombinant YGP40 (rYGP40), the potential precursor of the yolkin peptide complex. The ygp40 coding sequence was codon optimized, successfully expressed in the E. coli system, and purified from inclusion bodies with a yield of about 1.1 mg/L of culture. This study showed that the protein exhibits immunomodulatory activity, expressed by the stimulation of TNF-α and IL-10 production and nitric oxide induction at a level comparable to that of the natural yolkin peptide complex obtained by other authors from hen egg yolk. At the highest dose of 100 µg/mL, rYGP40 also caused the up-regulation of iNOS expression in murine bone marrow-derived macrophages (BMDM). Moreover, no cytotoxic effects of rYGP40 on the BMDM cell line were observed.

Activation of the iNOS/NO/cGMP pathway by Revactin® in human corporal smooth muscle cells

BackgroundThe combination of the nutraceuticals, Paullinia cupana, ginger rhizome, muira puama, and the amino acid L-citrulline (COMP-4) has been shown to stimulate the production of inducible nitric oxide synthase (iNOS), nitric oxide (NO), and cGMP in rat corpora cavernosa smooth muscle cells (CSMC). When administered to middle-aged rats, long-term treatment with COMP-4 resulted in both an increase in the number of CSMC and an improvement in erectile function. We, therefore, aimed to determine whether a commercial formulation of COMP-4, Revactin®, could have a similar stimulatory effect on human CSMC.MethodsPrimary human CSMC cultures (HCSMC) were grown and incubated with Revactin® for up to 24 hours. cGMP generation and nitrite formation were determined by ELISA and Griess reaction, respectively. IBMX (1 mM), sildenafil (0.4 mM), and L-NIL (4 µM) were utilized as modulators of the NO-cGMP pathway. iNOS, endothelial NOS (eNOS), and neuronal NOS (nNOS) expressions were determined by Western blot.ResultsRevactin® up-regulated both nitrite formation and cGMP expression, achieving the highest expression at 24 hours in the HCSMC. These effects were completely blocked by L-NIL. Revactin® up-regulated iNOS expression, but not that of eNOS or nNOS.ConclusionsThe results presented in this study confirmed that Revactin® activated the iNOS-NO-cGMP pathway intracellularly in HCSMC. It still needs to be determined whether the upregulation of this pathway would be an effective approach for counteracting the fibrosis and apoptosis of the corporal smooth muscle cells associated with aging.

Therapeutic effects of Durian wood bark extract on a rat model of rheumatoid arthritis

BackgroundRheumatoid arthritis (RA) is a common immune-mediated inflammatory disease characterized by increased inflammation of synovial joint, and often associated with disability. Although several studies have demonstrated the medicinal properties of durian, little is known about the role of durian wood bark for medicinal purposes. Thus, this study investigated the anti-arthritic activity of durian wood bark extract in a rat model of rheumatoid arthritis. MethodsThe rats were divided into five groups, including control, RA model, and RA model treated with durian wood bark extract (20, 30, and 40mg/kg/day for 14 days). The effects of treatment were evaluated by clinical, as well as histological changes in the ankle joints, and the expression level of inducible nitric oxide synthase (iNOS). ResultsA complete Freund's adjuvant (CFA)-induced RA model in rats was successfully, characterized by the swelling of hind limbs, histopathological changes in ankle joints, and the upregulation of iNOS expression. The administration of durian wood bark extract at a dose of 40mg/kg attenuated all parameters analyzed in CFA-induced RA model in rats. ConclusionAmelioration of hind limb swelling, histopathological changes, and iNOS expression in the RA model indicates that durian wood bark extract can be considered as a new treatment alternative that reduces joint symptoms, as well as a future area of research in humans.

Therapeutic effects of Durian wood bark extract on a rat model of rheumatoid arthritis

BackgroundRheumatoid arthritis (RA) is a common immune-mediated inflammatory disease characterized by increased inflammation of synovial joint, and often associated with disability. Although several studies have demonstrated the medicinal properties of durian, little is known about the role of durian wood bark for medicinal purposes. Thus, this study investigated the anti-arthritic activity of durian wood bark extract in a rat model of rheumatoid arthritis. MethodsThe rats were divided into five groups, including control, RA model, and RA model treated with durian wood bark extract (20, 30, and 40mg/kg/day for 14 days). The effects of treatment were evaluated by clinical, as well as histological changes in the ankle joints, and the expression level of inducible nitric oxide synthase (iNOS). ResultsA complete Freund's adjuvant (CFA)-induced RA model in rats was successfully, characterized by the swelling of hind limbs, histopathological changes in ankle joints, and the upregulation of iNOS expression. The administration of durian wood bark extract at a dose of 40mg/kg attenuated all parameters analyzed in CFA-induced RA model in rats. ConclusionAmelioration of hind limb swelling, histopathological changes, and iNOS expression in the RA model indicates that durian wood bark extract can be considered as a new treatment alternative that reduces joint symptoms, as well as a future area of research in humans.

HDAC6 Mediates Macrophage iNOS Expression and Excessive Nitric Oxide Production in the Blood During Endotoxemia.

Excessive nitric oxide (NO) production and NO-mediated nitrative stress contribute to vascular dysfunction, inflammation, and tissue injury in septic shock. New therapeutic targets are urgently needed to provide better control of NO level during septic shock. In the present study, we investigated the role of HDAC6 in the regulation of NO production and nitrative stress in a mouse model of endotoxin-induced septic shock. HDAC6 deficient mice and a specific HDAC6 inhibitor were utilized in our studies. Our data clearly indicate that HDAC6 is an important mediator of NO production in macrophages. HDAC6 mediates NO production through the regulation of iNOS expression in macrophages. HDAC6 up-regulates iNOS expression in macrophages by modulating STAT1 activation and IRF-1 expression. HDAC6 inhibition potently blocked endotoxin-induced STAT1 activation and iNOS expression in macrophages. Furthermore, HDAC6 contributes to excessive NO production and nitrotyrosine level in the blood and promotes iNOS expression in the lung tissues during septic shock. Our data reveal a novel HDAC6/STAT1/iNOS pathway that mediates excessive NO production and nitrative stress in septic shock.

Adoptive transfer of IFN-γ-induced M-MDSCs promotes immune tolerance to allografts through iNOS pathway.

Efficient production of monocytic myeloid-derived suppressor cells (M-MDSCs) with stable immunosuppressive function is crucial for immunomodulatory cell therapy for many diseases such as transplant rejection, graft-versus-host disease and autoimmune diseases. We used M-CSF as growth factor for myeloid progenitor cell differentiation and activated them with IFN-γ during early stage in vitro to produce M-MDSCs. The cell phenotypes were determined using flow cytometry, the immunosuppressive function and mechanisms were determined by skin grafted mouse models and genetic modified mice. IFN-γ treatment endows these cell strong immunosuppressive function by inhibition of T cell proliferation and cytokine productions. The phenotype of these cells also changed towards M-MDSCs. IFN-γ significantly upregulated iNOS expression in these M-MDSCs and inhibition of this molecule significantly reversed their immune regulatory function. The functional stability of induced M-MDSCs by IFN-γ was tested in vivo by transferring them to alloskin-grafted mice. Adoptive transfer of these cells significantly prolonged allograft survival and promoted immune tolerance, whereas iNOS deficiency in these cells reversed this effect. We established one M-MDSCs-inducting protocol with the combination of M-CSF and IFN-γ in vitro. M-CSF+IFN-γ-induced M-MDSCs are promising to prevent graft rejection by immune regulation.

Analysis of Macrophage Activation Markers in an Experimental Model of Cutaneous Leishmaniasis Treated with Photodynamic Therapy Mediated by 5-Aminolevulinic Acid.

Objective: In this study, we evaluated the effectiveness of photodynamic therapy (PDT) for the treatment of experimental cutaneous leishmaniasis (CL) and the profile of macrophages activation markers. Background: Leishmaniasis is an infectious disease caused by parasites of the genus Leishmania. CL is caused by Leishmania major in the old world and by Leishmania braziliensis in the Americas. Considering the targeted organs, PDT may constitute a valuable therapeutic intervention. Macrophages are the host cells of Leishmania in mammals and may be classified into type M1 or M2 depending on the pattern of activation. Methods: BALB/c mice were infected in the foot pad with 1 × 106 amastigotes of L. braziliensis and treated with 5-aminolevulinic acid (5-ALA), visible light, or 5-ALA-PDT. The ex vivo mRNA expression levels of interleukin-10, tumor necrosis factor-α (TNF-α), arginase-1, heme oxygenase ( Hmox), and induced nitric oxide synthase (iNOS) were quantities as markers of macrophage activation with distinct ability to kill intracellular parasite. Results: The parasite load decreased significantly in the group treated with PDT compared with the other groups. The iNOS relative mRNA was higher in the group treated with PDT and light only compared with the group without treatment, whereas iNOS/arginase ratio was significantly higher only in the PDT group. The expression of TNF-α was significantly higher in 5-ALA and light compared with PDT and control group. No significant difference was observed in the expression of the other markers evaluated. Conclusions: Both, light and 5-ALA-PDT were able to upregulate iNOS expression only; 5-ALA-PDT was able to reduce parasite burden. The increase in the iNOS levels suggests it might participate in the antimicrobial mechanisms triggered by 5-ALA-PDT; although parasite death mechanism was not completely clarified, the results presented in this study suggest that macrophage activation may contribute to parasite control.

GRK2 upregulates iNOS expression in microglia by mediating IRF1 and STAT1/3 activation

GRK2 upregulates iNOS expression in microglia by mediating IRF1 and STAT1/3 activation

A potential gliovascular mechanism for microglial activation: differential phenotypic switching of microglia by endothelium versus astrocytes

BackgroundActivation of microglia can result in phenotypic and functional diversity. However, the pathways that trigger different states of microglial activation remain to be fully understood. Here, we hypothesized that after injury, astrocytes and endothelium may contribute to a gliovascular switch for microglial activation.MethodsAstrocytes or cerebral endothelial cells were subjected to oxygen glucose deprivation, then conditioned media were transferred to microglia. The release of TNFα, IL-1β, IL-10, and IGF-1 was measured using ELISA. Surface markers of CD11b, CD45, CD86, and MHC class II were detected by flow cytometry. mRNA expression of iNOS, CD86, CD206, Arginase1, and transcription factors was measured using real-time PCR. Microglial function including migration and phagocytosis was assessed. Dendritogenesis was determined by counting the number of primary dendrites, secondary dendrites, and dendritic ends in the neurons exposed to either endothelial- or astrocyte-activated microglia.ResultsExposure to conditioned media from oxygen-glucose-deprived cerebral endothelial cells or oxygen-glucose-deprived astrocytes activated microglia into different forms. The endothelium converted ramified microglia into amoeboid shapes; increased the release of TNFα, IL-1β, and IL-10; decreased IGF-1; upregulated iNOS expression; and inhibited microglial migration and phagocytosis. In contrast, astrocytes increased microglial production of IGF-1, upregulated CD206 expression, and enhanced microglial phagocytosis. These opposing effects of the endothelium versus astrocyte crosstalk partly mirror potentially deleterious versus potentially beneficial microglial phenotypes. Consistent with this idea, endothelial-activated microglia were neurotoxic, whereas astrocyte-activated microglia did not affect neuronal viability but instead promoted neuronal dendritogenesis.ConclusionThese findings provide proof of concept that endothelial cells and astrocytes provide differing signals to microglia that influence their activation states and suggest that a gliovascular switch may be involved in the balance between beneficial versus deleterious microglial properties.

Cell-specific regulation of iNOS by AMP-activated protein kinase in primary rat hepatocytes

BackgroundAMP-activated protein kinase (AMPK) regulates several metabolic pathways in hepatocytes that are critical to the hepatic response to sepsis and shock. Induction of nitric oxide synthesis is an important response to sepsis, inflammation and shock and many of the stimuli that upregulate inducible nitric oxide synthase (iNOS) also activate AMPK. AMPK inhibits nitric oxide (NO) production in skeletal and cardiac muscle cells, but the role of AMPK in regulating iNOS expression in hepatocytes has not been determined. Materials and methodsPrimary cultured rat hepatocytes were preincubated with an AMPK inhibitor, AMPK activators, or transfected with AMPK siRNA before being treated with the proinflammatory cytokines interleukin-1β (IL-1β) and interferon-γ (IFNγ). The hepatocyte cell lysate and culture supernatants were collected for Western blot analysis and Griess assay. ResultsIL-1β and IFNγ markedly upregulated iNOS expression and AMPK phosphorylation. IL-1β + IFNγ–induced NO production and iNOS expression were significantly decreased in hepatocytes treated with the AMPK inhibitor compound C and AMPK knockdown by AMPK siRNA. Cytokine-induced iNOS expression was increased by AMPK activators 1-oxo-2-(2H-pyrrolium-1-yl)-1H-inden-3-olate, AMPK signaling activator III and AICA-riboside. Compound C upregulated Akt and c-Jun N-terminal kinase phosphorylation but decreased IκBα phosphorylation. AICA-riboside exerted opposite effects on these signaling pathways in hepatocytes. ConclusionsIn contrast to other cell types, AMPK increased IL-1β + IFNγ–induced NO production and iNOS expression through the Akt, c-Jun N-terminal kinase, and NF-κΒ signaling pathways in primary hepatocytes. These data suggest that AMPK-altering medications used clinically may have subsequent effects on iNOS expression and proinflammatory signaling pathways.

Effects of Sevoflurane on Hemodynamics and Inducible Nitric Oxide Synthase/Soluble Guanylate Cyclase Signaling Pathway in a Rat Model of Pulmonary Arterial Hypertension.

The effects of sevoflurane on right ventricular (RV) function are incompletely understood. In a rat model of experimentally induced pulmonary arterial hypertension (PAH), we studied effects of sevoflurane on RV function and the expression of inducible nitric oxide synthase/soluble guanylate cyclase (iNOS/sGC) signaling pathway. We hypothesized that sevoflurane would improve RV function in rats with PAH via a iNOS/sGC pathway. To induce PAH, Sprague-Dawley rats were randomly assigned to treatment with monocrotaline or normal saline. Four weeks later, rats were then randomly assigned to either control or sevoflurane inhalation. After rats were anesthetized and instrumented with a pulmonary artery or RV conductance catheter, they were treated with inhaled sevoflurane at 3 doses for 90 minutes each. Hemodynamic changes and expression of iNOS and sGC were recorded. Sevoflurane inhalation depressed RV function in both normal and PAH rats. However, RV dP/dtmax fell to a lesser degree in rats with PAH than normal rats. Sevoflurane inhalation increased iNOS expression, but decreased sGC expression. Sevoflurane depressed RV contractility to a lesser degree in PAH than in normal rats. Sevoflurane also upregulated iNOS expression and downregulated sGC expression in PAH, but not control rats. This observation may explain the differential effects of sevoflurane on RV function in rats with and without PAH.

In vitro characterization of grass carp (Ctenopharyngodon idella) IL-26 in regulating inflammatory factors

Interleukin 26 (IL-26) gene has been identified in human, amphibian and teleost but not in rodents. It is well accepted that IL-26 was a crucial member of IL-10 family which acts as a pro-inflammatory cytokine in human. However, the role of IL-26 in regulating inflammation in lower vertebrates including teleost has not been defined yet. In the present study, grass carp IL-26 (gcIL-26) coding sequence was isolated and identified. Its chromosomal synteny was also analyzed, showing that gcIL-26 gene is flanked by IL-22 and IFN-γ genes with the same transcriptional orientation as seen in human, amphibian and zebrafish. Given that zebrafish and grass carp IL-26 shared relatively low amino acid identities with human IL-26, the functional roles of fish IL-26 are indispensable to be elucidated. Accordingly, recombinant gcIL-26 (rgcIL-26) was prepared by using Pichia pastoris expression system, and it was found to be partially glycosylated. Using grass carp head kidney leucocytes as cell model, rgcIL-26 displayed the bioactivity to stimulate the mRNA expression of some pro-inflammatory cytokines including IL-8, IL-1β and IL-6, while inhibit mRNA expression of an anti-inflammatory cytokine, IL-10. Moreover, rgcIL-26 also up-regulated inos expression and NO production in grass carp monocytes/macrophages, strengthening its pro-inflammatory properties in fish. Those results collectively demonstrated the functional role of IL-26 in regulating inflammatory response in fish.

Therapeutic potential of carfilzomib, an irreversible proteasome inhibitor, against acetaminophen-induced hepatotoxicity in mice.

Overdose of acetaminophen (APAP) is often associated with hepatotoxicity. Carfilzomib (CFZ) shows multiple pharmacological activities including anti-inflammatory potential. Therefore, this study was undertaken to evaluate the possible therapeutic effects of CFZ against APAP-induced hepatotoxicity. Hepatotoxicity was induced by administration of APAP (350mg/kg, intraperitoneal). Mice were given CFZ (0.125, 0.25, or 0.5mg/kg, intraperitoneal) 1.5h after APAP administration. Animals were sacrificed on 6h and blood and liver tissue samples were collected for analysis. In CFZ-post-treated group, there was significant and dose-dependent decrease in serum alanine aminotransferase levels. The level of tumor necrosis factor-α (TNF-α), reactive oxygen species, and NO decreased, whereas glutathione increased significantly by CFZ post-treatment. Upregulated mRNA expression of COX-II and iNOS were significantly downregulated by CFZ post-treatment. CFZ may exert its hepatoprotective action by alleviating inflammatory, oxidative, and nitrosative stress via inhibition of TNF-α, COX-II, and iNOS.