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Steffen Gay

Publications and source records attributed to Steffen Gay.

At least 55 records · Page 3Linked to original sources
PubMed2005

Mechanisms of disease: the molecular and cellular basis of joint destruction in rheumatoid arthritis.

Rheumatoid arthritis is a complex systemic disease that ultimately leads to the progressive destruction of articular and periarticular structures. Novel data indicate that the innate immune system (through activation of Toll-like receptors) is involved in articular pathophysiology, including the recruitment of inflammatory cells, and that periarticular factors such as adipocytokines contribute to the perpetuation of joint inflammation. The deleterious process of joint destruction is mediated by intracellular signaling pathways involving transcription factors, such as nuclear factor kappaB, cytokines, chemokines, growth factors, cellular ligands, and adhesion molecules. Advances in molecular biology techniques have identified T-cell-independent and B-cell-independent pathways that operate at different stages of the disease. Cytokine-independent pathways appear to be responsible for maintaining basic disease activity that is not affected by currently available therapies. Using this knowledge in combination with gene-transfer and gene-silencing approaches, bench-to-bedside strategies will be developed, thus enabling the creation of novel treatments for rheumatoid arthritis.

Animals↗
PubMed2005

Nucleofection: a new, highly efficient transfection method for primary human keratinocytes*.

Transfection is an essential tool for numerous in vitro applications including studies of gene expression, promoter analysis, and intracellular signaling pathways and also for therapeutic strategies such as tissue engineering and gene therapy. However, transfection of primary cells including keratinocytes with common methods such as calcium phosphate, DEAE-dextran, liposome-mediated transfer, electroporation or viral vectors is problematic because of low transfection efficiency and the induction of terminal differentiation. Here we analyzed the use of nucleofection, a new, electroporation-based transfection method that enables the DNA to enter directly the nucleus, for the transfection of keratinocytes. Several different conditions were tested and optimized, resulting in a final transfection efficiency of 56% in primary human epidermal keratinocytes. This efficiency is superior to all non-viral transfection methods reported so far. The number of non-viable keratinocytes after nucleofection was low, varying between 14 and 16%. In contrast to other transfection protocols, nucleofection did not induce terminal differentiation in the transfected keratinocytes. In addition, nucleofection is a fast method, because the results can be analyzed within 7 h. In summary, nucleofection is a fast, easy and highly effective alternative for the transfection of primary human keratinocytes, which offers new opportunities for various research applications.

Benzothiazoles↗
PubMed2005

The role of synovial fibroblasts in mediating joint destruction in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic, inflammatory joint disease with systemic involvement that affects about 1% of the Western population. The progressive destruction of affected joints is a major characteristic of the disease and distinguishes RA from other acute and chronic arthritides. The etiology of RA is unknown, and a variety of genetic and environmental factors are being discussed as potential causes of the disease. However, in contrast to our incomplete understanding of the etiology, the knowledge about molecular mechanisms leading to joint destruction has advanced considerably over the past years. Thus, a large number of studies have investigated the presence and interplay of several types of cells in rheumatoid synovium, such as lymphocytes, macrophages and fibroblasts. They have led to the understanding that cells in the rheumatoid synovium form a network, which interacts through direct cell-to cell contacts as well as the release of a multitude of cytokines. The use of novel molecular techniques together with the development of new animal models has revised our concept on the pathogenesis of RA and specifically on the role of fibroblasts in initiation and progression of joint destruction. This article will review current data and hypotheses on disease mechanisms by which fibroblasts are involved in the destruction of joints in RA.

Animals↗
PubMed2004

Transfer of human leukocytes into double-knockout Pfp-/-Rag2-/- mice grafted with human skin: increased accumulation of neutrophils in human dermal microvessels.

Severe combined immunodeficient mice reconstituted with human leukocytes have been useful to model parts of the human immune system, including some of its diseases (e.g., AIDS). Because no human polymorphonuclear leukocytes (huPMN) develop in these xenograft models, diseases such as several forms of vasculitis cannot be modeled using this approach. To provide such a model for vasculitis, human skin patches were grafted onto double-knockout Pfp(-/-)Rag2(-/-) mice, which not only lack functional T and B cells but which are also devoid of natural killer cells. After intravenous injection, a high proportion of huPMNs survived within the circulation and accumulated in the human blood vessels. The accumulation increased considerably after the endothelium of the skin patches had been stimulated by tumor necrosis factor-alpha. Alpha mild perivascular neutrophilic infiltration and vascular necrosis was observed in the microvessels of the skin patches. Thus, a xenograft model of vasculitis with predominant huPMNs infiltration has been established for the first time.

Animals↗
PubMed2004

Synovial activation in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory disease with progressive articular damage. Activated cells of the synovium produce pro-inflammatory and matrix-degrading effector molecules, which maintain the inflammation and lead to the destruction of the involved joints. In addition to macrophages and T- and B-cells, fibroblast-like synoviocytes must be considered key cells in driving the pathological processes. They can be distinguished by their transformed-appearing phenotype and their invasion into adjacent cartilage and bone. Synovial activation is driven by pro-inflammatory cytokines as well as cytokine independent pathways including endogenous retroviral elements and Toll-like receptors (TLR). These pathways are connected by a complex network of autocrine and paracrine acting factors. Another feature of RA synovium is hyperplasia of the lining layer, which results from increased proliferation and decreased apoptosis of synovial fibroblasts. Thanks to new techniques in basic research, novel insights into the cellular and molecular mechanisms of the pathogenesis of RA were gained and led to the development of new, specific therapeutic strategies.

Animals↗
PubMed2004

Detection of synovial macrophages in an experimental rabbit model of antigen-induced arthritis: ultrasmall superparamagnetic iron oxide-enhanced MR imaging.

PURPOSE: To evaluate intravenously administered ultrasmall superparamagnetic iron oxide (USPIO) as a marker of macrophage activity in an experimental rabbit model of antigen-induced arthritis. MATERIALS AND METHODS: Unilateral arthritis was induced by means of intraarticular injection of methylated bovine serum albumin in 10 knees of 10 rabbits that had been presensitized to the same antigen. The contralateral knees in these rabbits, as well as six knees in three other rabbits, served as controls. After onset of arthritis, all knees were imaged prior to and 24 hours after administration of USPIO. The magnetic resonance (MR) imaging protocol included T1-weighted spin-echo, T2-weighted fast spin-echo, T2*-weighted gradient-echo, and short inversion time inversion-recovery sequences. Images were analyzed quantitatively and qualitatively with regard to signal characteristics and pattern. MR findings were correlated with histopathologic findings. Wilcoxon signed rank test was used to compare results of signal-to-noise ratio calculations before and after USPIO administration. RESULTS: All knees with intraarticular injection of antigen suspension developed unilateral arthritis, whereas no signs of arthritis occurred in the control knees. On USPIO-enhanced images obtained 24 hours after contrast agent administration, significant T1 (P =.03) and more predominantly T2* (P =.02) and T2 effects (P =.01) were evident in the synovium of all 10 arthritic knees, which reflected USPIO uptake by macrophages in the synovial tissue. To a lesser extent, T2* effects were present also within the joint effusion (P =.01). No significant changes in signal characteristics were detected in the 10 nonarthritic knees in the antigen-injected group or the six knees in the control group (P =.06-.91). Histologic examination confirmed uptake of iron in the macrophages of arthritic knees. Changes in MR signal characteristics within the arthritic synovium and synovial effusion were visually detectable after intravenous administration of USPIO. CONCLUSION: MR imaging at 1.5 T can depict USPIO uptake in phagocytic-active macrophages in an antigen-induced arthritis animal model.

Adjuvants, Immunologic↗
PubMed2004

Uncontrolled expression of vascular endothelial growth factor and its receptors leads to insufficient skin angiogenesis in patients with systemic sclerosis.

Systemic sclerosis (SSc) skin lesions are characterized by disturbed vessel morphology with enlarged capillaries and an overall reduction in capillary density, suggesting a deregulated, insufficient angiogenic response. It has been postulated that this phenomenon is due to reduced expression of the potent angiogenic factor vascular endothelial growth factor (VEGF). In contrast to this hypothesis, we demonstrate that the expression of both VEGF and its receptors VEGFR-1 and VEGFR-2 is dramatically upregulated in skin specimens of SSc patients throughout different disease stages. Interestingly, upregulation of VEGF was not mediated by hypoxia-inducible transcription factor-1 (HIF-1) as indicated by only a weak expression of the oxygen-sensitive alpha-subunit of HIF-1 in the skin of SSc patients. This was unexpected on measuring low Po2 values in the SSc skin by using a polarographic oxygen microelectrode system. Considering our observation that PDGF and IL-1beta costimulated VEGF expression, we propose that chronic and uncontrolled VEGF upregulation that is mediated by an orchestrated expression of cytokines rather than VEGF downregulation is the cause of the disturbed vessel morphology in the skin of SSc patients. Consequently, for therapeutic approaches aiming to improve tissue perfusion in these patients, a controlled expression and timely termination of VEGF signaling appears to be crucial for success of proangiogenic therapies.

Cell Hypoxia↗
PubMed2004

Chemokine secretion of rheumatoid arthritis synovial fibroblasts stimulated by Toll-like receptor 2 ligands.

To analyze the role of Toll-like receptors (TLR) in the pathogenesis of rheumatoid arthritis, we have assessed the effects of stimulation of cultured synovial fibroblasts by the TLR-2 ligand bacterial peptidoglycan. By using high density oligonucleotide microarray analysis we identified 74 genes that were up-regulated >2.5-fold. Fourteen CC and CXC chemokine genes were among the genes with the highest up-regulation. Quantitative real-time PCR analysis confirmed up-regulation of granulocyte chemotactic protein (GCP)-2, RANTES, monocyte chemoattractant protein (MCP)-2, IL-8, growth-related oncogene-2, and to a lesser extent, macrophage-inflammatory protein 1alpha, MCP-1, EXODUS, and CXCL-16. GCP-2, RANTES, and MCP-2 were detected in culture supernatants of synovial fibroblasts stimulated with peptidoglycan. Chemokine secretion induced by stimulation of rheumatoid arthritis synovial fibroblasts via TLR-2 was functionally relevant as demonstrated by chemotaxis assays. GCP-2 and MCP-2 expression, which have not been reported previously in rheumatoid arthritis, was demonstrated in synovial tissue sections of patients diagnosed with rheumatoid arthritis but not in those with osteoarthritis. Correspondingly, synovial fluid levels were significantly higher in patients diagnosed with rheumatoid arthritis as compared with osteoarthritis. Thus, we present evidence for an induction of chemokine secretion by activation of synovial fibroblasts via TLR-2, possibly contributing to the formation of inflammatory infiltrates characteristically found in rheumatoid arthritis joints.

Adult↗
PubMed2004

Ribozymes that inhibit the production of matrix metalloproteinase 1 reduce the invasiveness of rheumatoid arthritis synovial fibroblasts.

OBJECTIVE: To investigate whether retroviral gene transfer of ribozymes targeting matrix metalloproteinase 1 (MMP-1) inhibits the production of MMP-1 in rheumatoid arthritis synovial fibroblasts (RASFs) and reduces the invasiveness of these cells in vivo. METHODS: MMP-1-specific ribozymes (RzMMP-1) were designed and cloned into the pLNSX retroviral vector. Cleavage of MMP-1 was determined in vitro, and the most effective ribozyme was selected for further investigation. RASFs were transduced with replication-deficient viruses carrying RzMMP-1 or with empty viruses (mock). Quantitative polymerase chain reaction with cleavage site-spanning fluorescent probes was used to measure the levels of MMP-1, MMP-9, and MMP-13 messenger RNA. In addition, protein levels of MMP-1 in cell culture supernatants were determined by enzyme linked immunosorbent assay. The effects of stimulation with lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNFalpha) on the production of MMP-1 were assessed accordingly. The invasiveness of RzMMP-1-transduced, mock-transduced, and untransduced RASFs was analyzed in the SCID mouse in vivo model of RA. RESULTS: Transduction of RASFs with RzMMP-1 significantly decreased the production of MMP-1 in RASFs without affecting other MMPs, such as MMP-9 and MMP-13. RzMMP-1 not only reduced the spontaneous production of MMP-1, but also prevented the LPS- and TNFalpha-induced increase in MMP-1 production. Inhibition of MMP-1 was maintained for at least 2 months and was accompanied by a significant reduction of the invasiveness of RASFs in the SCID mouse model of RA. CONCLUSION: Intracellular expression of ribozymes constitutes a feasible tool for inhibiting the production of matrix-degrading enzymes. Inhibition of MMP-1 alone results in a significant reduction of cartilage invasion by RASFs.

Animals↗
PubMed2004

Expression of interleukin-21 receptor, but not interleukin-21, in synovial fibroblasts and synovial macrophages of patients with rheumatoid arthritis.

OBJECTIVE: To determine the role and expression of the cytokine/receptor pair interleukin-21 (IL-21)/IL-21 receptor (IL-21R) in rheumatoid arthritis (RA). METHODS: The expression of IL-21R and IL-21 was analyzed by TaqMan real-time polymerase chain reaction (PCR) and in situ hybridization of synovial biopsy samples from patients with RA and osteoarthritis (OA). Double labeling by immunohistochemistry after in situ hybridization was performed with anti-CD68 antibodies. The expression of IL-21R at the protein level was confirmed by Western blotting. Stimulation experiments were performed with recombinant IL-1beta, tumor necrosis factor alpha (TNFalpha), platelet-derived growth factor (PDGF), and transforming growth factor beta (TGFbeta). The role of IL-21R in cartilage destruction was analyzed in the SCID mouse coimplantation model of RA. RESULTS: IL-21R was found in total RNA extracts and in synovial biopsy samples from RA patients, whereas no expression or only minimal expression was seen in samples from OA patients. Double labeling indicated that both synovial macrophages and synovial fibroblasts expressed IL-21R. Western blotting with anti-IL-21R antibodies confirmed the expression of IL-21R protein in RA synovial fibroblasts (RASFs). Of note, IL-21 was not detectable by real-time PCR and in situ hybridization in the same samples in vivo as in vitro. The level of expression of IL-21R messenger RNA (mRNA) was not altered by stimulation with IL-1beta, TNFalpha, PDGF, or TGFbeta. Interestingly, in the SCID mouse coimplantation model, RASFs did not maintain their expression of IL-21R at sites of invasion into the cartilage. Similarly, IL-21R mRNA was not expressed at sites of invasion into cartilage and bone in RA synovium. CONCLUSION: Our data demonstrate that IL-21R is expressed in RA synovium by RASFs and synovial macrophages. IL-21R is associated with the activated phenotype of RASFs independently of the major proinflammatory cytokines IL-1beta and TNFalpha, but correlates negatively with the destruction of articular cartilage and bone.

Animals↗
PubMed2004

Cooperation of Ras- and c-Myc-dependent pathways in regulating the growth and invasiveness of synovial fibroblasts in rheumatoid arthritis.

OBJECTIVE: To study the specific contribution of MAP kinase activator c-Raf-1 and one of its downstream transcription factors, c-Myc, to the growth and invasive behavior of rheumatoid arthritis synovial fibroblasts (RASFs). METHODS: RASFs were transduced with retroviral constructs expressing dominant-negative mutants of c-Raf-1 or c-Myc (DN c-Raf-1 or DN c-Myc, respectively) or with the mock vector. The expression of wild-type and mutant proteins was confirmed by Western blotting. Growth curves of RASFs were recorded, and apoptosis was measured by flow cytometry. Invasiveness of RASFs was assessed in the SCID mouse model of RA. Immunohistochemistry was used to study the effects of DN c-Raf-1 on phosphorylated c-Jun and matrix metalloproteinase 1 (MMP-1) in RASFs implanted into SCID mice. The phosphorylation of ERK and JNK in DN c-Raf-1- and mock-transduced RASFs was determined in vitro by Western blotting. The levels of MMPs in these cells were measured by quantitative polymerase chain reaction (PCR). RESULTS: Neither DN c-Raf-1 alone nor DN c-Myc alone significantly altered proliferation or apoptosis of RASFs, but both mutants together rapidly induced apoptosis. Inhibition of c-Raf-1 or c-Myc significantly reduced the invasiveness of RASFs in the SCID mouse model. DN c-Raf-1 decreased the phosphorylation of ERK and JNK in vitro and reduced the in vivo expression of phosphorylated c-Jun as well as the expression of disease-relevant MMPs. As determined by quantitative PCR, the inhibition was most pronounced for MMP-1 and MMP-3. CONCLUSION: The data demonstrate that Ras- and c-Myc-dependent signaling events cooperate to regulate the growth and invasiveness of RASFs. Targeting of both c-Raf-1 and c-Myc may constitute an interesting therapeutic approach in RA.

Animals↗
PubMed2004

The L1 retroelement-related p40 protein induces p38delta MAP kinase.

We characterized a full length L1 mRNA in a rheumatoid arthritis (RA) synovial tissue and determined the degree of methylation of its 5'-UTR. We asked whether not only intact but also altered L1s can exert biological activities by transfecting RA synovial fibroblasts (SF) with either retrotransposition-competent or incompetent L1s and examined their capacity to induce p38delta. Total RNA was isolated from the synovial tissue of a 35-year-old woman with highly destructive RA. A complete L1 sequence was obtained by 3'/5'-RACE. Methylation of the genomic 5'-UTR was determined by the sodium-disulfide/PCR method. RA-SF were transfected by lipofection with either a functional L1 or an ORF2-mutated L1 element. The expression of p38delta was measured by RT-PCR and Western blot. The full length L1 mRNA included a 5'-UTR, an ORF1 and an ORF2. Three of five CpG islands (60%) of the genomic L1 5'-UTR were hypomethylated and the ORF2 was deactivated by the insertion of stop codons. Both, intact and ORF2-mutated L1 vectors, induced the expression of p38delta. Thus, even an ORF2-mutated L1 element, as expressed in RA, is biologically active and both L1 ORF1 and p38delta transcripts may appear as a consequence of genomic hypomethylation. The induction of p38delta appears to be mediated by an ORF1/p40-dependent process. This is the first indication of a p40 mediated transactivation.

Arthritis, Rheumatoid↗
PubMed2004

Functional genomics of fibroblasts.

PURPOSE OF REVIEW: Successful analysis of the pathophysiology of rheumatoid arthritis requires the functional understanding of interactions between different cell types and the cell matrix, intracellular signaling pathways, as well as between cartilage, bone, and synovium in rheumatoid arthritis. During the review period, molecular biology has provided and used a growing number of tools to screen the genome such as gene and protein chips, haplotype analysis, and single nucleotide polymorphism analysis, resulting in various novel findings with considerable impact on the overall understanding of rheumatoid arthritis. RECENT FINDINGS: Key issues that have been addressed and elucidated by numerous research groups are the regulation and modulation of synovial fibroblast metabolism and activation by proinflammatory cytokines and chemokines. In addition, examination of adhesion processes and neoangiogenesis has revealed new insights into the interaction network between rheumatoid synovial fibroblasts and the surrounding matrix and cells. Finally, a more detailed view of activation of these fibroblasts has been obtained by analysis of the molecular balance between cellular activation and regulation of apoptosis. SUMMARY: Although high throughput molecular analysis methods provided an ample amount of novel data, it needs to be stressed that a one-method approach of gene expression (eg, by array analysis) is not sufficient to validate the gene/gene product as a new therapeutic target. Therefore, the next steps are the so-called functional genomics or functionomics, which intend to reveal relations between the obtained data and to unveil their interactions for a better understanding of the pathogenesis and the mechanisms that are operative in rheumatoid arthritis.

Apoptosis↗
PubMed2004

Pattern recognition receptors and their involvement in the pathogenesis of arthritis.

PURPOSE OF REVIEW: Pattern recognition receptors are germ-line encoded receptors that recognize specific pathogen-associated molecules, thereby allowing the innate immune system to distinguish self from nonself structures. Pattern recognition receptors mediate activation of different signaling pathways, resulting in the production of proinflammatory cytokines and the expression of antimicrobial genes. Additionally, pattern recognition receptors play a central role in the activation and direction of the adaptive immune response. This review summarizes recent advances in research trying to elucidate the link between different pattern recognition receptors and inflammatory autoimmune disorders. RECENT FINDINGS: The best known pattern recognition receptors, the toll-like receptors, are involved in the regulation of inflammation during infectious diseases. They affect apoptotic pathways and dendritic cell maturation, and interact with B-cell receptors in priming T-cell responses to host-derived DNA. This brought toll-like receptors and other pattern recognition receptors into focus as potential players in the induction of autoimmune diseases. Indeed, several inflammatory autoimmune diseases have been linked during the past few years to defects or polymorphisms of genes encoding pattern recognition receptors. SUMMARY: The discovery of toll-like receptors and other groups of pattern recognition receptors, such as the caspase recruitment domains or the triggering receptors expressed by myeloid cells, allowed one to draw an increasingly complex picture of immune responses to pathogens. The growing evidence for an involvement of pattern recognition receptors in the pathogenesis of autoimmune disorders warrants further investigation of the expression and function of pattern recognition receptors to develop novel therapeutics for diseases such as rheumatoid arthritis.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Bucillamine induces the synthesis of vascular endothelial growth factor dose-dependently in systemic sclerosis fibroblasts via nuclear factor-kappaB and simian virus 40 promoter factor 1 pathways.

The pathogenesis of systemic sclerosis (SSc) is characterized by activation of the immune system, impaired angiogenesis, and activated dermal fibroblasts. The effects of the immunosuppressive agent bucillamine (SA 96) on fibroblasts and angiogenic factors have not been examined. SA 96, and particularly its metabolite SA 981, increased the levels of vascular endothelial growth factor (VEGF) mRNA and protein dose-dependently in dermal fibroblasts from patients with SSc and healthy control subjects without influencing cell viability. SSc fibroblast cultures showed consistently a higher inducibility of VEGF than cultures from healthy control subjects. Preincubation with the SP-1 inhibitor mithramycin as well as blockade of nuclear factor (NF)-kappaB signaling with pyrrolidine dithiocarbamate treatment and IkappaB transfection reduced significantly the transcription of VEGF, indicating that both transcription factors contribute to the activation of VEGF by SA 981. Specific binding of NF-kappaB protein to its binding site after treatment with SA 981 was confirmed by electrophoretic mobility shift assay. In contrast, SA 981 did not influence the stability of VEGF mRNA as analyzed with actinomycin D assays. The study provides evidence for a role of NF-kappaB in the transcriptional regulation of the VEGF gene. SA 96 might have positive aspects on the impaired angiogenesis in patients with SSc.

Cells, Cultured↗
PubMed2003

Differential effects of selective cyclooxygenase-2 inhibitors on endothelial function in salt-induced hypertension.

BACKGROUND: In view of the ongoing controversy about potential differences in cardiovascular safety of selective cyclooxygenase (COX)-2 inhibitors (coxibs), we compared the effects of 2 different coxibs and a traditional NSAID on endothelial dysfunction, a well-established surrogate of cardiovascular disease, in salt-induced hypertension. METHODS AND RESULTS: Salt-sensitive (DS) and salt-resistant (DR) Dahl rats were fed a high-sodium diet (4% NaCl) for 56 days. From days 35 to 56, diclofenac (6 mg x kg(-1) x d(-1); DS-diclofenac), rofecoxib (2 mg x kg(-1) x d(-1); DS-rofecoxib), celecoxib (25 mg x kg(-1) x d(-1); DS-celecoxib) or placebo (DS-placebo) was added to the chow. Blood pressure increased with sodium diet in the DS groups, which was more pronounced after diclofenac and rofecoxib treatment (P<0.005 versus DS-placebo) but was slightly decreased by celecoxib (P<0.001 versus DS-placebo). Sodium diet markedly reduced NO-mediated endothelium-dependent relaxations to acetylcholine (10-10-10-5 mol/L) in aortic rings of untreated hypertensive rats (P<0.005 versus DR-placebo). Relaxation to acetylcholine improved after celecoxib (P<0.005 versus DS-placebo and DS-rofecoxib) but remained unchanged after rofecoxib and diclofenac treatment. Vasoconstriction after nitric oxide synthase inhibition, indicating basal NO release, with N(omega)-nitro-L-arginine methyl ester (10-4 mol/L) was blunted in DS rats (P<0.05 versus DR-placebo), normalized by celecoxib, but not affected by rofecoxib or diclofenac. Indicators of oxidative stress, 8-isoprostane levels, were elevated in untreated DS rats on 4% NaCl (6.55+/-0.58 versus 3.65+/-1.05 ng/mL, P<0.05) and normalized by celecoxib only (4.29+/-0.58 ng/mL). CONCLUSIONS: These data show that celecoxib but not rofecoxib or diclofenac improves endothelial dysfunction and reduces oxidative stress, thus pointing to differential effects of coxibs in salt-induced hypertension.

Acetylcholine↗