Transcriptional and post-transcriptional regulation of iNOS expression in human chondrocytes

Chondrocytes are important for the development and maintenance of articular cartilage. However, both in osteoarthritis (OA) and rheumatoid arthritis (RA) chondrocytes are involved in the process of cartilage degradation and synthesize important immunomodulatory mediators, including nitric oxide (NO) generated by the inducible NO synthase (iNOS). To uncover the role of iNOS in the pathomechanisms of OA and RA, we analyzed the regulation of iNOS expression using immortalized human chondrocytes as a reproducible model. In C-28/I2 chondrocytes, iNOS expression was associated with the expression of the chondrocyte phenotype. Peak induction by a cytokine cocktail occurred between 6 and 8h and dec…

Tristetraprolin Regulates the Expression of the Human Inducible Nitric-Oxide Synthase Gene

The expression of human inducible NO synthase (iNOS) is regulated both by transcriptional and post-transcriptional mechanisms. Stabilization of mRNAs often depends on activation of p38 mitogen-activated protein kinase (p38 MAPK). In human DLD-1 cells, inhibition of p38 MAPK by the compound 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580) or by overexpression of a dominant-negative p38 MAPKalpha protein resulted in a reduction of human iNOS mRNA and protein expression, whereas human iNOS promoter activity was not affected. An important RNA binding protein regulated by the p38 MAPK pathway and involved in the regulation of the stability of several mRNAs is tr…

Urinary bladder enlargement across nine rodent models of diabetes: correlations with glucose and insulin levels

AbstractThe urinary bladder is markedly enlarged in the type 1 diabetes mellitus model of streptozotocin (STZ)-injected rats, but much less data exist for models of type 2 diabetes (T2DM). Diabetic polyuria has been proposed to explain bladder enlargement. We have collected data on bladder weight and blood glucose from 16 studies representing 9 distinct rodent diabetes (7 T2DM) and obesity models; some included arms with diets and/or pharmacological treatments. Data were analyzed for bladder enlargement and for correlations between bladder weight on the one and glucose levels on the other hand. Our data confirm major bladder enlargements in STZ rats, minor if any enlargement in fructose-fed…

Regulation of NOS expression in vascular diseases

Nitric oxide synthases (NOS) are the major sources of nitric oxide (NO), a small bioactive molecule involved in the regulation of many cellular processes. One of the most prominent functions of NO is regulation of vasodilatation and thereby control of blood pressure. Most important for vascular tone is NOS3. Endothelial NOS3-generated NO diffuses into the vascular smooth muscle cells, activates the soluble guanylate cyclase resulting in enhanced cGMP concentrations and smooth muscle cell relaxation. However, more and more evidence exist that also NOS1 and NOS2 contribute to vascular function. We summarize the current knowledge about the regulation of NOS expression in the vasculature by tra…

Endothelial Dysfunction in Tristetraprolin-deficient Mice Is Not Caused by Enhanced Tumor Necrosis Factor-α Expression

Cardiovascular events are important co-morbidities in patients with chronic inflammatory diseases like rheumatoid arthritis. Tristetraprolin (TTP) regulates pro-inflammatory processes through mRNA destabilization and therefore TTP-deficient mice (TTP(-/-) mice) develop a chronic inflammation resembling human rheumatoid arthritis. We used this mouse model to evaluate molecular signaling pathways contributing to the enhanced atherosclerotic risk in chronic inflammatory diseases. In the aorta of TTP(-/-) mice we observed elevated mRNA expression of known TTP targets like tumor necrosis factor-α (TNF-α) and macrophage inflammatory protein-1α, as well as of other pro-atherosclerotic mediators, l…

The RNA binding protein tristetraprolin influences the activation state of murine dendritic cells

Abstract Dendritic cells (DCs) serve to maintain peripheral tolerance under steady state conditions. Upon triggering by activation signals they initiate strong immune responses. The activation of DCs is accompanied by a rapid upregulation of proinflammatory cytokines, which were shown in other cell types to be regulated by mechanisms at the transcriptional and posttranscriptional level. Tristetraprolin (TTP), an important RNA binding protein, is involved in the regulation of mRNA stability of such cytokines. In this study we analyzed the significance of TTP for mouse DCs, which were derived from TTP −/− and WT bone marrow progenitor cells (BM-DCs). Unstimulated BM-DCs of TTP −/− mice expres…

Involvement of KSRP in the post-transcriptional regulation of human iNOS expression–complex interplay of KSRP with TTP and HuR

We purified the KH-type splicing regulatory protein (KSRP) as a protein interacting with the 3'-untranslated region (3'-UTR) of the human inducible nitric oxide (iNOS) mRNA. Immunodepletion of KSRP enhanced iNOS 3'-UTR RNA stability in in vitro-degradation assays. In DLD-1 cells overexpressing KSRP cytokine-induced iNOS expression was markedly reduced. In accordance, downregulation of KSRP expression increases iNOS expression by stabilizing iNOS mRNA. Co-immunoprecipitations showed interaction of KSRP with the exosome and tristetraprolin (TTP). To analyze the role of KSRP binding to the 3'-UTR we studied iNOS expression in DLD-1 cells overexpressing a non-binding mutant of KSRP. In these ce…

Mitochondrial oxidative stress and nitrate tolerance – comparison of nitroglycerin and pentaerithrityl tetranitrate in Mn-SOD+/- mice

Abstract Background Chronic therapy with nitroglycerin (GTN) results in a rapid development of nitrate tolerance which is associated with an increased production of reactive oxygen species (ROS). According to recent studies, mitochondrial ROS formation and oxidative inactivation of the organic nitrate bioactivating enzyme mitochondrial aldehyde dehydrogenase (ALDH-2) play an important role for the development of nitrate and cross-tolerance. Methods Tolerance was induced by infusion of wild type (WT) and heterozygous manganese superoxide dismutase mice (Mn-SOD+/-) with ethanolic solution of GTN (12.5 μg/min/kg for 4 d). For comparison, the tolerance-free pentaerithrityl tetranitrate (PETN, 1…

Regulation of the Expression of Inducible Nitric Oxide Synthase

Publisher Summary This chapter reveals how nitric oxide (NO) generated by the inducible isoform of nitric oxide synthase (iNOS) exerts multiple beneficial microbicidal, antiviral, antiparasital, complex immunomodulatory, and antitumoral effects. Aberrant iNOS induction in the wrong place or at the wrong time has detrimental consequences and it is involved in the pathophysiology of several human diseases. Therefore, iNOS has to be regulated very tightly. The inducible isoform of NOS is mainly regulated at the level of expression. The mechanisms regulating iNOS expression involve modulation of promoter activity, mRNA stability and translatability, and protein stability. Modulation of iNOS exp…

Interferon-γ Induces Chronic Active Myocarditis and Cardiomyopathy in Transgenic Mice

Chronic heart failure is associated with an activation of the immune system characterized among other factors by the cardiac synthesis and serum expression of proinflammatory cytokines. There is unequivocal clinical and experimental evidence that the cytokine tumor necrosis factor-alpha is involved in the development of chronic heart failure, but a putative cardiotoxic potential of the proinflammatory cytokine interferon (IFN)-gamma remains primarily unknown. To investigate this issue we analyzed the cardiac phenotype of SAP-IFN-gamma transgenic mice, which constitutively express IFN-gamma in their livers and hence exhibit high circulating serum levels of this cytokine. SAP-IFN-gamma mice s…

Induction of tolerogenic lung CD4+ T cells by local treatment with a pSTAT-3 and pSTAT-5 inhibitor ameliorated experimental allergic asthma.

Signal transducer and activator of transcription (STAT)-3 inhibitors play an important role in regulating immune responses. Galiellalactone (GL) is a fungal secondary metabolite known to interfere with the binding of phosphorylated signal transducer and activator of transcription (pSTAT)-3 as well of pSTAT-6 dimers to their target DNA in vitro. Intra nasal delivery of 50 μg GL into the lung of naive Balb/c mice induced FoxP3 expression locally and IL-10 production and IL-12p40 in RNA expression in the airways in vivo. In a murine model of allergic asthma, GL significantly suppressed the cardinal features of asthma, such as airway hyperresponsiveness, eosinophilia and mucus production, after…

Regulation of the expression of inducible nitric oxide synthase

Nitric oxide (NO) generated by the inducible isoform of nitric oxide synthase (iNOS) is involved in complex immunomodulatory and antitumoral mechanisms and has been described to have multiple beneficial microbicidal, antiviral and antiparasital effects. However, dysfunctional induction of iNOS expression seems to be involved in the pathophysiology of several human diseases. Therefore iNOS has to be regulated very tightly. Modulation of expression, on both the transcriptional and post-transcriptional level, is the major regulation mechanism for iNOS. Pathways resulting in the induction of iNOS expression vary in different cells or species. Activation of the transcription factors NF-kappaB an…

The polypyrimidine tract-binding protein (PTB) is involved in the post-transcriptional regulation of human inducible nitric oxide synthase expression.

Human inducible nitric oxide synthase (iNOS) expression is regulated by transcriptional and post-transcriptional mechanisms. We have recently shown that the multifunctional RNA-binding proteins KH-type splicing regulatory protein and tristetraprolin are critically involved in the post-transcriptional regulation of human iNOS expression. Several reports have shown that KH-type splicing regulatory protein colocalizes with the polypyrimidine tract-binding protein (PTB), and both RNA-binding proteins seem to interact with the same mRNAs. Therefore we analyzed the involvement of PTB in human iNOS expression. In human DLD-1 cells, cytokine incubation necessary to induce iNOS expression did not ch…

Regulation of human inducible nitric oxide synthase expression by an upstream open reading frame.

Abstract The human inducible nitric oxide synthase (iNOS) gene contains an upstream open reading frame (uORF) in its 5′-untranslated region (5′-UTR) implying a translational regulation of iNOS expression. Transfection experiments in human DLD-1 cells revealed that the uORF although translatable seems not to inhibit the translation start at the bona fide ATG. Our data clearly show that human iNOS translation is cap-dependent and that the 5′-UTR of the iNOS mRNA contains no internal ribosome entry site. Translation of the bona fide coding sequence is most likely mediated by a leaky scanning mechanism. The 5′-UTR is encoded by exon 1 and exon 2 of the iNOS gene with the uORF stop codon located…

Regulation of the expression of inducible nitric oxide synthase

The role of nitric oxide (NO) generated by the inducible isoform of nitric oxide synthase (iNOS) is very complex. Induction of iNOS expression and hence NO production has been described to have beneficial antiviral, antiparasital, microbicidal, immunomodulatory, and antitumoral effects. However, induced at the wrong place or at the wrong time, iNOS has detrimental consequences and seems to be involved in the pathophysiology of different human diseases. The pathways regulating iNOS expression seem to vary in different cells or different species. In general, activation of the transcription factors nuclear factor (NF)-kappaB and signal transducer and activator of transcription (STAT)-1alpha an…

The KH-type splicing regulatory protein (KSRP) regulates type III interferon expression post-transcriptionally.

Abstract Type III interferons (IFNs) are the latest members of the IFN family. They play an important role in immune defense mechanisms, especially in antiviral responses at mucosal sites. Moreover, they control inflammatory reactions by modulating neutrophil and dendritic cell functions. Therefore, it is important to identify cellular mechanisms involved in the control of type III IFN expression. All IFN family members contain AU-rich elements (AREs) in the 3′-untranslated regions (3′-UTR) of their mRNAs that determine mRNA half-life and consequently the expressional level of these cytokines. mRNA stability is controlled by different proteins binding to these AREs leading to either stabili…

Regulation of Human Mitochondrial Aldehyde Dehydrogenase (ALDH-2) Activity by Electrophiles in Vitro

Recently, mitochondrial aldehyde dehydrogenase (ALDH-2) was reported to reduce ischemic damage in an experimental myocardial infarction model. ALDH-2 activity is redox-sensitive. Therefore, we here compared effects of various electrophiles (organic nitrates, reactive fatty acid metabolites, or oxidants) on the activity of ALDH-2 with special emphasis on organic nitrate-induced inactivation of the enzyme, the biochemical correlate of nitrate tolerance. Recombinant human ALDH-2 was overexpressed in Escherichia coli; activity was determined with an HPLC-based assay, and reactive oxygen and nitrogen species formation was determined by chemiluminescence, fluorescence, protein tyrosine nitration,…

One Enzyme, Two Functions

The human enzyme paraoxonase-2 (PON2) has two functions, an enzymatic lactonase activity and the reduction of intracellular oxidative stress. As a lactonase, it dominantly hydrolyzes bacterial signaling molecule 3OC12 and may contribute to the defense against pathogenic Pseudomonas aeruginosa. By its anti-oxidative effect, PON2 reduces cellular oxidative damage and influences redox signaling, which promotes cell survival. This may be appreciated but also deleterious given that high PON2 levels reduce atherosclerosis but may stabilize tumor cells. Here we addressed the unknown mechanisms and linkage of PON2 enzymatic and anti-oxidative function. We demonstrate that PON2 indirectly but specif…

Knockout of the KH-Type Splicing Regulatory Protein Drives Glomerulonephritis in MRL-Faslpr Mice

KH-type splicing regulatory protein (KSRP) is an RNA-binding protein that promotes mRNA decay and thereby negatively regulates cytokine expression at the post-transcriptional level. Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by dysregulated cytokine expression causing multiple organ manifestations

Similar Regulation of Human Inducible Nitric-oxide Synthase Expression by Different Isoforms of the RNA-binding Protein AUF1

The ARE/poly-(U) binding factor 1 (AUF1), a protein family consisting of four isoforms, is believed to mediate mRNA degradation by binding to AU-rich elements (ARE). However, evidence exists that individual AUF1 isoforms may stabilize ARE-containing mRNAs. The 3'-untranslated region of the human inducible nitric-oxide synthase (iNOS) contains five AREs, which promote RNA degradation. We have recently shown that the RNA-binding protein KSRP is critically involved in the decay of the iNOS mRNA. In this study we examined the effects of the individual AUF1 isoforms on iNOS expression. Overexpression of each AUF1 isoform reduces iNOS expression on mRNA and protein levels to the same extent by mo…

Effects of nitroglycerin or pentaerithrityl tetranitrate treatment on the gene expression in rat hearts: evidence for cardiotoxic and cardioprotective effects.

Nitroglycerin (NTG) and pentaerithrityl tetranitrate (PETN) are organic nitrates used in the treatment of angina pectoris, myocardial infarction, and congestive heart failure. Recent data show marked differences in the effects of NTG and PETN on the generation of reactive oxygen species. These differences are attributed to different effects of NTG and PETN on the expression of antioxidative proteins like the heme oxygenase-I. To analyze the expressional effects of NTG and PETN in a more comprehensive manner we performed whole genome expression profiling experiments using cardiac total RNA from NTG- or PETN-treated rats and DNA microarrays containing oligonucleotides representing 27,044 rat…

Vascular Dysfunction in Experimental Diabetes Is Improved by Pentaerithrityl Tetranitrate but Not Isosorbide-5-Mononitrate Therapy

OBJECTIVE Diabetes is associated with vascular oxidative stress, activation of NADPH oxidase, and uncoupling of nitric oxide (NO) synthase (endothelial NO synthase [eNOS]). Pentaerithrityl tetranitrate (PETN) is an organic nitrate with potent antioxidant properties via induction of heme oxygenase-1 (HO-1). We tested whether treatment with PETN improves vascular dysfunction in the setting of experimental diabetes. RESEARCH DESIGN AND METHODS After induction of hyperglycemia by streptozotocin (STZ) injection (60 mg/kg i.v.), PETN (15 mg/kg/day p.o.) or isosorbide-5-mononitrate (ISMN; 75 mg/kg/day p.o.) was fed to Wistar rats for 7 weeks. Oxidative stress was assessed by optical methods and o…

The fungal lactone oxacyclododecindione is a potential new therapeutic substance in the treatment of lupus-associated kidney disease.

Recently oxacyclododecindione (Oxa), a macrocyclic lactone isolated from the imperfect fungus Exserohilum rostratum, has been described as a potent transcription inhibitor of inducible proinflammatory and profibrotic genes in cell culture models. As kidney disease in systemic lupus erythematosus is characterized by aberrant expression of inflammatory mediators and infiltration of immune cells, we investigated the effect of Oxa in MRL-Fas(lpr) mice, a model of systemic lupus erythematosus. These mice develop a spontaneous T-cell and macrophage-dependent autoimmune disease including severe glomerulonephritis that shares features with human lupus. Comparable to the results of in vitro models, …

The human fascin gene promoter is highly active in mature dendritic cells due to a stage-specific enhancer.

Abstract Dendritic cells (DC), regarded as the most efficient APCs of the immune system, are capable of activating naive T cells. Thus, DC are primary targets in immunotherapy. However, little is known about gene regulation in DC, and for efficient transcriptional targeting of human DC, a suitable promoter is still missing. Recently, we successfully used the promoter of the murine actin-bundling protein fascin to transcriptionally target DC by DNA vaccination in mice. In this study, we report on isolation of the human fascin promoter and characterization of its regulatory elements. The actively expressed gene was distinguished from a conserved inactive genomic locus and a continuous region …

Tristetraprolin regulation of interleukin-22 production

AbstractInterleukin (IL)-22 is a STAT3-activating cytokine displaying characteristic AU-rich elements (ARE) in the 3′-untranslated region (3′-UTR) of its mRNA. This architecture suggests gene regulation by modulation of mRNA stability. Since related cytokines undergo post-transcriptional regulation by ARE-binding tristetraprolin (TTP), the role of this destabilizing protein in IL-22 production was investigated. Herein, we demonstrate that TTP-deficient mice display augmented serum IL-22. Likewise, IL-22 mRNA was enhanced in TTP-deficient splenocytes and isolated primary T cells. A pivotal role for TTP is underscored by an extended IL-22 mRNA half-life detectable in TTP-deficient T cells. Lu…

NOX2ko Mice Show Largely Increased Expression of a Mutated NOX2 mRNA Encoding an Inactive NOX2 Protein

Background: The superoxide-generating enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX2 or gp91phox, the phagocytic isoform) was reported as a major source of oxidative stress in various human diseases. Genetic deletion is widely used to study the impact of NOX2-derived reactive oxygen species (ROS) on disease development and progression in various animal models. Here, we investigate why NOX2 knockout mice show no NOX2 activity but express NOX2 mRNA and protein. Methods and Results: Oxidative burst (NOX2-dependent formation of ROS) was measured by L-012-based chemiluminescence and was largely absent in whole blood of NOX2 knockout mice. Protein expression was still de…

The anti-inflammatory fungal compound (S)-curvularin reduces proinflammatory gene expression in an in vivo model of rheumatoid arthritis.

In previous studies, we identified the fungal macrocyclic lactone (S)-curvularin (SC) as an anti-inflammatory agent using a screening system detecting inhibitors of the Janus kinase/signal transducer and activator of transcription pathway. The objective of the present study was to investigate whether SC is able to decrease proinflammatory gene expression in an in vivo model of a chronic inflammatory disease. Therefore, the effects of SC and dexamethasone were compared in the model of collagen-induced arthritis (CIA) in mice. Total genomic microarray analyses were performed to identify SC target genes. In addition, in human C28/I2 chondrocytes and MonoMac6 monocytes, the effect of SC on proi…

Post-Transcriptional Regulation of Human Inducible Nitric-Oxide Synthase Expression by the Jun N-terminal Kinase

Human inducible nitric-oxide synthase (iNOS) expression is regulated both at transcriptional and post-transcriptional levels. In the present study, the effect of Jun N-terminal kinase (JNK) on human iNOS expression was investigated. In A549/8 human alveolar epithelial cells, both the inhibition of JNK by a pharmacological inhibitor anthra[1,9-cd]pyrazol-6(2H)-one1,9-pyrazoloanthrone (SP600125) and small interfering RNA (siRNA)-mediated down-regulation of JNK led to a reduction of iNOS mRNA and protein expression. iNOS promoter activity was not affected by these treatments. Hence, JNK seems to regulate iNOS expression through post-transcriptional mechanisms by stabilizing iNOS mRNA. Our labo…

ALDH-2 deficiency increases cardiovascular oxidative stress--evidence for indirect antioxidative properties.

Abstract Mitochondrial aldehyde dehydrogenase (ALDH-2) reduces reactive oxygen species (ROS) formation related to toxic aldehydes; additionally, it provides a bioactivating pathway for nitroglycerin. Since acetaldehyde, nitroglycerin, and doxorubicin treatment provoke mitochondrial oxidative stress, we used ALDH-2−/− mice and purified recombinant human ALDH-2 to test the hypothesis that ALDH-2 has an indirect antioxidant function in mitochondria. Antioxidant capacity of purified ALDH-2 was comparable to equimolar doses of glutathione, cysteine, and dithiothreitol; mitochondrial oxidative stress was comparable in C57Bl6 and ALDH-2−/− mice after acute challenges with nitroglycerin or doxorubi…

Human inducible nitric oxide synthase (iNOS) expression depends on chromosome region maintenance 1 (CRM1)- and eukaryotic translation initiation factor 4E (elF4E)-mediated nucleocytoplasmic mRNA transport

Human inducible nitric oxide synthase (iNOS) is regulated on the expressional level mostly by post-transcriptional mechanisms modulating the mRNA stability. Another important step in the control of eukaryotic gene expression is the nucleocytoplasmic mRNA transport. Most cellular mRNAs are exported via the TAP/Nxt complex of proteins. However, some mRNAs are transported by a different mechanism involving the nuclear export receptor CRM1. Treatment of DLD-1 cells with the CRM1 inhibitor leptomycin B (LMB) or anti-CRM1 siRNAs reduced cytokine-induced iNOS expression. We could demonstrate that the iNOS mRNA is exported from the nucleus in a CRM1-dependent manner. Since CRM1 itself does not poss…

Chronic inflammatory cardiomyopathy of interferon γ-overexpressing transgenic mice is mediated by tumor necrosis factor-α.

We recently described a model of inflammatory cardiomyopathy in interferon (IFN)-γ overexpressing transgenic mice stably circulating IFN-γ in the serum referred to as SAP–-IFN-γ mice. SAP–IFN-γ transgenic mice show cardiac infiltration by mononuclear leukocytes, culminating in dilated cardiomyopathy characterized by an increase of left ventricular end diastolic diameter and reduction of fractional shortening. We hypothesized that the pathological mechanism underlying SAP–IFN-γ cardiomyopathy might be mediated by (auto)immune processes or tumor necrosis factor (TNF)-α synthesis from IFN-γ–activated macrophages. To verify these hypotheses, we crossed SAP–IFN-γ transgenic mice with immunodefic…

Resveratrol post-transcriptionally regulates pro-inflammatory gene expression via regulation of KSRP RNA binding activity

Resveratrol shows beneficial effects in inflammation-based diseases like cancer, cardiovascular and chronic inflammatory diseases. Therefore, the molecular mechanisms of the anti-inflammatory resveratrol effects deserve more attention. In human epithelial DLD-1 and monocytic Mono Mac 6 cells resveratrol decreased the expression of iNOS, IL-8 and TNF-α by reducing mRNA stability without inhibition of the promoter activity. Shown by pharmacological and siRNA-mediated inhibition, the observed effects are SIRT1-independent. Target-fishing and drug responsive target stability experiments showed selective binding of resveratrol to the RNA-binding protein KSRP, a central post-transcriptional regul…

Pentaerythrityl Tetranitrate and Nitroglycerin, but not Isosorbide Mononitrate, Prevent Endothelial Dysfunction Induced by Ischemia and Reperfusion

Background— Short term exposure to nitroglycerin (GTN) has protective properties that are similar to ischemic preconditioning. Whether other organic nitrates such as pentaerithrityl tetranitrate (PETN) and isosorbide mononitrate (ISMN) have similar protective effects has not been explored. Methods and Results— In a randomized, parallel, double blind, controlled trial, 37 healthy young volunteers received no therapy (n=10), transdermal GTN 1.2 mg for 2 hours (n=9), PETN 80 mg (n=9), or ISMN 40 mg (n=9). Twenty-four hours later, endothelium-dependent flow-mediated vasodilation (FMD) was measured before and after local exposure to ischemia and reperfusion (IR). In the no therapy group, IR blu…

Post-transcriptional regulation of the human inducible nitric oxide synthase (iNOS) expression by the cytosolic poly(A)-binding protein (PABP).

Affinity purification using the 3'-untranslated region (3'-UTR) of the human inducible nitric oxide synthase (iNOS) mRNA identified the cytosolic poly(A)-binding protein (PABP) as a protein interacting with the human iNOS 3'-UTR. Downregulation of PABP expression by RNA interference resulted in a marked reduction of cytokine-induced iNOS mRNA expression without changes in the expression of mRNAs coding for the major subunit of the RNA polymerase II (Pol 2A) or β2-microglobuline (β2M). Along with the mRNA also iNOS protein expression was reduced by siPABP-treatment, whereas in the same cells protein expression of STAT-1α, NF-κB p65, or GAPDH was not altered. Reporter gene analyses showed no …

Inactivation of the KSRP gene modifies collagen antibody induced arthritis.

Abstract The KH type splicing regulatory protein (KSRP) is a nucleic acid binding protein, which negatively regulates the stability and/or translatability of many mRNA species encoding immune-relevant proteins. As KSRP is expressed in immune cells including T and B cells, neutrophils, macrophages and dendritic cells, we wanted to analyze its importance for the development of autoimmune diseases. We chose collagen antibody-induced arthritis (CAIA) as an appropriate autoimmune disease mouse model in which neutrophils and macrophages constitute the main effector cell populations. We compared arthritis induction in wild type (WT) and KSRP−/− mice and paws were taken for histological sections an…

Artichoke, Cynarin and Cyanidin Downregulate the Expression of Inducible Nitric Oxide Synthase in Human Coronary Smooth Muscle Cells

Artichoke (Cynara scolymus L.) is one of the world’s oldest medicinal plants with multiple health benefits. We have previously shown that artichoke leaf extracts and artichoke flavonoids upregulate the gene expression of endothelial-type nitric oxide synthase (eNOS) in human endothelial cells. Whereas NO produced by the eNOS is a vasoprotective molecule, NO derived from the inducible iNOS plays a pro-inflammatory role in the vasculature. The present study was aimed to investigate the effects of artichoke on iNOS expression in human coronary artery smooth muscle cells (HCASMC). Incubation of HCASMC with a cytokine mixture led to an induction of iNOS mRNA expression. This iNOS induction was c…

Regulation of Human ALDH-2 Activity by Electrophiles – Implications for Organic Nitrate Induced Tolerance, Oxidative Stress and Reactive Fatty Acid Metabolites in MI

PS5:100 Patophysiological role of type i and iii interferons in systemic lupus erythematosus (sle)

Systemic Lupus erythematosus (SLE) is an autoimmune disease characterised by activated autoreactive lymphocytes and autoantibodies, resulting in tissue damage in multiple organs. An important factor for the disease´s mortality is the development of Lupus nephritis (LN). Type I and III interferons, which are both part of the antiviral defense, have both been associated with the disease´s activity. In sera and urine of SLE patients an enhanced level of IL28/29 was described, but their distinct functional role in the course of disease need to be further investigated. To determine the role of type I and III interferons during onset and progression of autoimmunity – with focus on the development…