Search

In experimental arthritis, glucocorticoid secretion is inadequate relative to inflammation. We hypothesized that IL-1 is a key factor for inadequate glucocorticoid secretion in arthritic rats. Collagen type II—induced arthritis (CIA) in DA rats was the model to study effects of IL-1 on adrenal function. In the CIA model, an increase of intraadrenal MHCII-positive cells was observed. MHCII-positive cells or bone marrow-derived dendritic cells inhibited glucocorticoid secretion of adrenal gland cells. IL-1, but also IL-18 and the inflammasome were critical in glucocorticoid inhibition. Arthritic compared to control adrenal gland cells produced higher amounts of CXC chemokines from MHCII+ adrenal cells, particularly CINC-2, which is strongly dependent on presence of IL-1. In CIA, macrophages and/or dendritic cells inhibit glucocorticoid secretion via IL-1 in adrenal glands. These findings show that activated macrophages and/or dendritic cells inhibit glucocorticoid secretion in experimental arthritis and that IL-1β is a decisive factor.

Epigenetic modifiers of the histone deacetylase (HDAC) family contribute to autoimmunity, cancer, HIV infection, inflammation, and neurodegeneration. Hence, histone deacetylase inhibitors (HDACi), which alter protein acetylation, gene expression patterns, and cell fate decisions, represent promising new drugs for the therapy of these diseases. Whereas pan-HDACi inhibit all 11 Zn2+-dependent histone deacetylases (HDACs) and cause a broad spectrum of side effects, specific inhibitors of histone deacetylase 6 (HDAC6i) are supposed to have less side effects. We present the synthesis and biological evaluation of Marbostats, novel HDAC6i that contain the hydroxamic acid moiety linked to tetrahydro-β-carboline derivatives. Our lead compound Marbostat-100 is a more potent and more selective HDAC6i than previously established well-characterized compounds in vitro as well as in cells. Moreover, Marbostat-100 is well tolerated by mice and effective against collagen type II induced arthritis. Thus, Marbostat-100 repr...

Objectives: The appearance of endogenous tyrosine hydroxylase-positive cells (TH+ cells) in collagen-induced arthritis was associated with an anti-inflammatory effect. Here we investigated putative anti-inflammatory and antinociceptive effects of the transfer of induced, bone marrow stem cell-derived TH+ cells (iTH+ cells) on murine antigen-induced arthritis (AIA). Methods: Bone marrow-derived stem cells were differentiated into iTH+ cells. These cells were transferred to mice immunized against methylated bovine serum albumin (mBSA) 2 days before AIA was induced by injection of mBSA into one knee joint. In AIA control mice and iTH+-treated mice the severity of AIA, pain-related behavior, humoral and cellular responses, and the invasion of macrophages into the dorsal root ganglia were assessed. Results: The intravenous transfer of iTH+ cells before AIA induction did not cause a sustained suppression of AIA severity but significantly reduced inflammation-evoked pain-related behavior. The iTH+ cells used for transfer exhibited enormous production of interleukin-4. A major difference between AIA control mice and iTH+-treated AIA mice was a massive invasion of the dorsal root ganglia by iNOS-negative, arginine 1-positive macrophages corresponding to an M2 phenotype. The differences in other cellular and humoral immune parameters such as release of cytokines from stimulated lymphocytes between AIA control mice and iTH+-treated mice were small. Conclusions: The transfer of iTH+ cells may cause a long-lasting reduction of arthritis-induced pain even if it does not ameliorate inflammation. The invasion of M2 macrophages into the dorsal root ganglia is likely to be an important mechanism of antinociception.

OBJECTIVE Patients with chronic inflammatory autoimmune diseases benefit from a broad spectrum of immunosuppressive and antiproliferative medication available today. However, nearly all of these therapeutic compounds have unwanted toxic side effects. Recent knowledge about the neurobiology of placebo responses indicates that associative learning procedures can be utilized for dose reduction in immunopharmacotherapy while simultaneously maintaining treatment efficacy. This study was undertaken to examine whether and to what extent a 75% reduction of pharmacologic medication in combination with learned immunosuppression affects the clinical outcome in a rodent model of type II collagen-induced arthritis. METHODS An established protocol of taste-immune conditioning was applied in a disease model of chronic inflammatory autoimmune disease (type II collagen-induced arthritis) in rats, where a novel taste (saccharin; conditioned stimulus [CS]) was paired with an injection of the immunosuppressive drug cyclosporin A (CSA) (unconditioned stimulus [US]). Following conditioning with 3 CS/US pairings (acquisition), the animals were immunized with type II collagen and Freund's incomplete adjuvant. Fourteen days later, at the first occurrence of clinical symptoms, retrieval was started by presenting the CS together with low-dose CSA as reminder cues to prevent the conditioned response from being extinguished. RESULTS This "memory-updating" procedure stabilized the learned immune response and significantly suppressed disease progression in immunized rats. Clinical arthritis score and histologic inflammatory symptoms (both P < 0.05) were significantly diminished by learned immunosuppression in combination with low-dose CSA (25% of the full therapeutic dose) via β-adrenoceptor-dependent mechanisms, to the same extent as with full-dose (100%) pharmacologic treatment. CONCLUSION These results indicate that learned immunosuppression appears to be mediated via β-adrenoceptors and might be beneficial as a supportive regimen in the treatment of chronic inflammatory autoimmune diseases by diminishing disease exacerbation.

Objectives In collagen type II-induced arthritis (CIA), early activation of the sympathetic nervous system (SNS) is proinflammatory. Here, we wanted to find new target organs contributing to proinflammatory SNS effects. In addition, we wanted to clarify the importance of SNS-modulated immunocyte migration. Methods A new technique termed spatial energy expenditure configuration (SEEC) was developed to demonstrate bodily areas of high energy demand (to find new targets). We studied homing of labeled cells in vivo, lymphocyte expression of CCR7, supernatant concentration of CCL21, and serum levels of sphingosine-1-phosphate (S1P) in sympathectomized control/arthritic animals. Results During the course of arthritis, SEEC identified an early marked increase of energy expenditure in draining lymph nodes and spleen (nowhere else!). Although early sympathectomy ameliorated later disease, early sympathectomy increased energy consumption, organ weight, and cell numbers in arthritic secondary lymphoid organs, possibly a sign of lymphocyte retention (also in controls). Elimination of the SNS retained lymph node cells, elevated expression of CCR7 on lymph node cells, and increased CCL21. Serum levels of S1P, an important factor for lymphocyte egress, were higher in arthritic than control animals. Sympathectomy decreased S1P levels in arthritic animals to control levels. Transfer of retained immune cells from draining lymph nodes of sympathectomized donors to sympathectomized recipients markedly increased arthritis severity over weeks. Conclusions By using the SEEC technique, we identified draining lymph nodes and spleen as major target organs of the SNS. The data show that the SNS increases egress of lymphocytes from draining lymph nodes to stimulate arthritic inflammation.

Previously, we reported that cervical vagal nerve stimulation (VNS) increases blood glucose levels and inhibits insulin secretion in anesthetized rats through afferent signaling. Since afferent signaling is also thought to mediate the therapeutic effects of VNS in patients with therapy‐refractory epilepsy and major depression, the question arises if patients treated with VNS develop impaired glucose tolerance. Thus, we hypothesized that cervical VNS impairs glucose tolerance in conscious rats. Rats (n = 7) were instrumented with telemetric blood pressure sensors and right‐ or left‐sided cervical vagal nerve stimulators (3 V, 5 Hz, 1 msec pulse duration, 1 h on 1 h off). Glucose tolerance tests (GTTs, 1.5 g dextrose/kg BW, i.p.) were performed after overnight fasting with the stimulators on or off (sham stimulation) in randomized order separated by 3–4 days. Overnight VNS did not alter mean levels of blood pressure or heart rate, but increased fasted blood glucose levels (140 ± 13 mg/dL vs. 109 ± 8 mg/dL, P

Objective. Treg cells modulate immune responses and can suppress the development of autoimmune diseases. Tumor necrosis factor receptor II (TNFRII) has been recognized as a key receptor on these cells that facilitates expansion and stabilization of CD4+ Treg cells. The purpose of the present study was to investigate the therapeutic activity of a novel TNFRII agonist in experimental arthritis as well as the role of different Treg cell subsets. Methods. A novel mouse TNFRII-selective fusion protein (EHD2-sc-mTNF(R2)) was generated by genetic engineering. Mouse T cells were incubated together with interleukin-2 and/or EHD2-sc-mTNF(R2), and the effects on Treg cells were analyzed by flow cytometry. Mice with collagen-induced arthritis (CIA) were treated with EHD2-sc-mTNF(R2) or saline, and the therapeutic effects were monitored and characterized. Results. Selective activation of TNFRII was found to expand both CD4+ and CD8+ Treg cells. Moreover, TNFRII activation elevated the number of CD4+CD25+ and CD8+CD25+ Treg cells and increased the number of FoxP3-expressing cells in CD8+, but not CD4+, Treg cells, indicating different mechanisms of TNFRII-induced expansion of diverse T cell subsets with suppressive activity. In the CIA model, we demonstrated that administration of the TNFRII agonist EHD2-sc-mTNF(R2) led to the expansion of both CD4+ and CD8+ Treg cells invivo and induced anti-inflammatory responses that alleviated arthritis. Conclusion. Our findings support the use of TNFRII-selective therapeutics as an effective approach to the treatment of arthritic disease and possibly other inflammatory and autoimmune diseases.

In rheumatoid and collagen-induced arthritis (CIA) relative insufficiency of adrenal glands (AG) in later stages of the disease is known. Additionally, migration of macrophages and dendritic cells (DCs) into AG has been described. We hypothesized that these cells contribute to inadequate glucocorticoid secretion. CIA was induced in DA rats. Cytokines in supernatants from whole AG cells, AG cells after magnetic bead separation for macrophage/DC markers MHCII and CD11b, and from bone marrow-derived DCs (BMDC) were quantified with ELISA. The corticosterone secretion from whole AG cells in co-culture with BMDCs was quantified with ELISA. BMDCs generated from arthritic rats expressed significantly more IL-1b, CINC-1,-2,-3, and LIX (all p

Blacklegged ticks (Ixodes scapularis) transmit the causative agent of Lyme disease in the Northeastern and upper Midwestern US. Current research focuses on elucidating biochemical pathways which may be disrupted to prevent pathogen transmission, thereby preventing disease. A genome screening process reported transcripts coding for two putative sulfotransferases in salivary glands of adult Ixodes scapularis and in whole tick extracts of the nymphal and larval stages. Sulfotransferases are known to sulfonate phenolic and alcoholic receptor agonists such as 17β-estradiol, thereby inactivating the receptor ligands. We used bioinformatic approaches to predict substrates for these two sulfotransferases (designated Ixosc Sult 1 and Ixosc Sult 2), and tested the predictions with biochemical assays. Amino acid sequence analysis showed that Ixosc Sult 1 and 2 are members of the cytosolic sulfotransferase superfamily. Homology models of 3D-protein structure were prepared for each tick sulfotransferase based on sulfotransferase X-ray crystal structures. Visualization of the electrostatic surface of the ligand binding cavities showed regions of negative electrostatic charge. Molecular docking identified potential substrates including dopamine, R-octopamine and S-octopamine, which docked into Ixosc Sult 1 with favorable binding affinity and correct conformation for sulfonation. Dopamine, but not R- or S-octopamine, also docked into Ixosc Sult 2 in a catalytic binding mode. Other molecules including 17β-estradiol, pregnenolone and serotonin, did not dock in catalytically active position to either protein. The predictions were tested and confirmed using cytosolic fractions of extracts of whole ticks. Dopamine was found to be a good substrate (Km 0.1 – 0.4 μM) for the native Ixodes scapularis sulfotransferases from larval and nymphal stages regardless of their fed/unfed status. Octopamine–sulfonation was only detected after feeding when gene expression data suggests that only Ixosc Sult 1 is present. These results agree with the docking predictions that octopamine is sulfonated only by Ixosc Sult 1, whereas dopamine is sulfonated by both Ixosc Sult 1 and Sult 2. Because dopamine is known to stimulate salivation in ticks through receptor stimulation, these results imply that the function/s of Ixosc Sult 1 or Sult 2 in the Ixodid tick may include inactivation of the salivation signal via sulfonation of dopamine and/or octopamine.

Background So far, there exists no golden standard for the treatment of arthrofibrosis (AF) following total knee arthroplasty (TKA). Although pain is a hallmark of AF, nociceptive nerve fibers have never been investigated in affected joint tissue. Methods A total of 24 patients with osteoarthritis (OA) of the knee (n = 12) and post-TKA AF of the knee (n = 12) were included. Along evaluation of typical clinical signs and symptoms by using the Knee Society Clinical Rating System (KSS), the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC index), the innervation of joint tissue was studied by semiquantitative immunofluorescence of nerve fibers. Results Patients with AF compared to OA had a lower KSS and lower KOOS. In all compartments (anterior, medial, and lateral recesses), the density of synovial sympathetic nerve fibers was significantly higher in OA compared to AF, which was also true for the density of sensory nerve fibers in the medial and lateral recesses. In synovial tissue of the anterior recess of patients with AF compared to OA, the density of nociceptive sensory nerve fibers was significantly higher relative to sympathetic nerve fibers. This was similarly observed in the neighboring infrapatellar fat pad of the knee. Conclusions Similar as in many painful musculoskeletal diseases, this study indicates that patients with arthrofibrosis of the knee after TKA demonstrate a preponderance of profibrotic sensory nerve fibers over antifibrotic sympathetic nerve fibers. This could serve as a starting point for AF therapy with specific antifibrotic pain medication or regional anesthetic techniques.

Introduction: Density of sympathetic nerve fibers decreases in inflamed arthritic tissue tested by immunoreactivity towards tyrosine-hydroxylase (TH, catecholaminergic key enzyme). Since sympathetic nerve fibers can change phenotype from catecholaminergic to cholinergic (example: sweat glands, periosteum),[for full text, please go to the a.m. URL], 43. Kongress der Deutschen Gesellschaft für Rheumatologie (DGRh); 29. Jahrestagung der Deutschen Gesellschaft für Orthopädische Rheumatologie (DGORh); 25. wissenschaftliche Jahrestagung der Gesellschaft für Kinder- und Jugendrheumatologie (GKJR)

In an established paradigm of taste-immune conditioning in the rat, the novel taste saccharine (conditioned stimulus/CS) is combined with an i.p. injection of the immunosuppressive drug cyclosporine A (CsA; unconditioned stimulus/US). With this paradigm we analyzed in two experimental settings conditioned immunosuppressive effects on collagen type II induced arthritis as a model of chronic inflammatory autoimmune diseases. In both experiments, four different groups of rats were conditioned with three CS/US pairings starting nine days prior to induction of arthritis. During the first experiment animals were re-exposed to the CS at day 13 after immunization. Our data show that CS re-exposure led to a significant reduction of the clinical and histological arthritis score. This effect was accompanied by an inhibition of splenic CD3 stimulated T cell cytokine production. In the second experiment retrieval started one day after immunization before emergence of the first arthritis symptoms. Significant differences in the clinical score between conditioned animals and controls where only seen in the acute phase of the disease. These results essentially indicated that in conditioned immunosuppression the time point of retrieval is important for the beneficial outcome on inflammatory joint diseases. Moreover, in a third upcoming experiment, retrieval of the conditioned response will be initiated after the first symptoms occur, analyzing more clinically relevant aspects.

Sympathetic nerve fibers innervate bone and tissue adjacent to joints. They play an important role in bone and tissue homeostasis. Under certain conditions, sympathetic nerve fibers can change their phenotype from catecholaminergic to cholinergic. This can be important because anti-inflammatory effects of acetylcholine have been described (alpha-7-nicotinic receptor). We asked whether this transition might occur in the joint during collagen-induced arthritis (CIA) in mice or during rheumatoid arthritis (RA) and osteoarthritis (OA) in humans. Sections of limbs from 30 immunized mice and synovial tissue samples obtained from 30 OA and 12 RA patients were stained for tyrosine hydroxylase (noradrenergic fibers), and for vesicular acetylcholine transporter (cholinergic fibers). In mouse joint area, an increase in the ratio of cholinergic to catecholaminergic nerve fibers appeared at day 35 after immunization. Most of the nerve fibers were located in joint-adjacent skin or muscle tissue, and only very few were detected in synovial tissue or near erosions. In human tissue sections, we were able to show cholinergic fibers in the synovium of four OA patients but in none of the RA patients. Co-culture of sympathetic ganglia and osteoclast progenitors from healthy mice showed more catecholaminergic-to-cholinergic transition when compared to experiments with osteoclast progenitors from arthritic mice. In mice and men, catecholaminergic-to-cholinergic transition is possible in less synovial inflamed tissue but not in highly inflamed arthritic tissue.

Sympathetic and sensory nerve fibers innervate bone and joint adjacent tissue. Apart from transmitting signals to the brain (afferent function), they also play an important role in bone homeostasis (efferent function). Under certain conditions sympathetic nerve fibers are able to change their phenotype from noradrenergic to cholinergic. Anti-inflammatory effects mediated by the α7 subunit-containing nicotinic acetylcholine receptor have been described (work of Tracey’s group). We asked whether this transition might occur near focal erosions during collagen-induced arthritis (CIA) in mice or in co-culture experiments of murine sympathetic ganglia and osteoclast progenitor cells. Limbs from 30 immunized C57Bl/6J mice were collected at distinct time points covering all stages of the disease. Sections of limbs from CIA experiments as well as sympathetic ganglia from co-culture experiments were stained for tyrosine hydroxylase (TH), the key enzyme for catecholamine synthesis (noradrenergic fibers), and vesicular acetylcholine transporter (VAChT, cholinergic fibers) by immunofluorescence. In mouse joint sections, an increase in the ratio of cholinergic to adrenergic nerve fiber density at day 35 after immunization was observed. However, most of the nerve fibers were located in joint adjacent skin or muscle tissue, only few in synovium or directly in the erosion. Co-culture experiments of sympathetic ganglia and osteoclast progenitors obtained from healthy mice showed increased cholinergic activity as compared to experiments with cells from mice with CIA. Taken together, these results suggest that cholinergic innervation in the joint region is upregulated under inflammatory conditions and that catecholaminergic nerve fibers are influenced by osteoclast progenitor cells.