Histamine H1 receptors on adherent rheumatoid synovial cells in culture: demonstration by radioligand binding and inhibition of histamine-stimulated prostaglandin E production by histamine H1 antagonists

Histamine and Histamine H4 Receptor Promotes Osteoclastogenesis in Rheumatoid Arthritis

Histamine H4 receptor (H4R) has immune-modulatory and chemotaxic effects in various immune cells. This study aimed to determine the osteoclastogenic role of H4R in rheumatoid arthritis (RA). The concentration of histamine in synovial fluid (SF) and sera in patients with RA was measured using ELISA. After RA SF and peripheral blood (PB) CD14+ monocytes were treated with histamine, IL-17, IL-21 and IL-22, and a H4R antagonist (JNJ7777120), the gene expression H4R and RANKL was determined by real-time PCR. Osteoclastogenesis was assessed by counting TRAP–positive multinucleated cells in PB CD14+ monocytes cultured with histamine, Th17 cytokines and JNJ7777120. SF and serum concentration of histamine was higher in RA, compared with osteoarthritis and healthy controls. The expression of H4R was increased in PB monocytes in RA patients. Histamine, IL-6, IL-17, IL-21 and IL-22 induced the expression of H4R in monocytes. Histamine, IL-17, and IL-22 stimulated RANKL expression in RA monocytes and JNJ7777120 reduced the RANKL expression. Histamine and Th17 cytokines induced the osteoclast differentiation from monocytes and JNJ7777120 decreased the osteoclastogenesis. H4R mediates RANKL expression and osteoclast differentiation induced by histamine and Th17 cytokines. The blockage of H4R could be a new therapeutic modality for prevention of bone destruction in RA.

Receptor mediation and nociceptin inhibition of bradykinin-induced plasma extravasation in the knee joint of the rat

OBJECTIVE AND DESIGN

The aim was to investigate the signaling mechanisms and regulation of bradykinin (BK)-induced inflammation in rat knee joint.

MATERIALS AND METHODS

Knee joints of anesthetized rats were perfused with BK (0.1-1.0 microM), and synovial plasma extravasation (PE) was evaluated by spectrophotometrical measurement of Evans Blue leakage. To examine the signaling pathway, B1 antagonist [des-Arg10]-HOE140 (0.1-1.0 microM) and B2 antagonist HOE140 (0.05-1.0 microM), calcitonin gene-related peptide (CGRP) antagonist CGRP8-37 (0.5-1.0 microM), prostaglandin E2 antagonist AH-6809 (0.1-1.0 microM), and histamine H1 antagonist mepyramine (0.1-1.0 microM) were used. Nociceptin (0.0001-1.0 microM) and antagonist J-113397 were tested for modulation of BK-induced PE. The analyses were compared side-by-side with 5-hydroxytryptamine-induced PE.

RESULTS

BK perfusion dose-dependently induced PE, which was blocked by HOE140, CGRP8-37, AH-6809, and mepyramine. It was also inhibited by nociceptin, which could be reversed by antagonist J-113397. In contrast, 5-hydroxytryptamine-induced PE was biphasically regulated by nociceptin and was not antagonized by CGRP8-37.

CONCLUSIONS

BK-induced PE is mediated by B2 receptors and may involve CGRP, prostaglandin, and histamine pathways. BK-induced PE is inhibited by nociceptin through the activation of ORL1 receptors. There are differences between BK- and 5-hydroxytryptamine-induced inflammation in signaling and modulation.

Effect of histamine on the production of matrix metalloproteinases-1, -3, -8 and -13, and TNF? and PGE2 by human articular chondrocytes and synovial fibroblasts in vitro: a comparative study

Histamine has many regulatory activities and is well recognised for its importance in allergic and inflammatory disorders. Recently, histamine has been implicated in the pathophysiological processes of both rheumatoid and osteoarthritis, where human articular chondrocytes (HACs) and rheumatoid synovial fibroblasts (RSFs) are reported to express histamine receptors. This study has demonstrated H(1) and H(2) histamine receptors using immunohistochemistry on HACs and RSFs in vitro and has compared the effects of histamine (20 microM) on both cell types with regard to the production of matrix metalloproteinases (MMPs-1, -3, -8 and -13), the proinflammatory cytokine tumour necrosis factor alpha (TNFalpha) and prostaglandin E(2) (PGE(2)). On incubation with histamine, HACs showed increased production of MMP-3, MMP-13, TNFalpha and PGE(2) (statistical significance P=0.02, 0.005, 0.008 and 0.03, respectively, student's t-test), but MMP-1 expression was unaffected. In contrast, the RSF showed a histamine-induced increase in MMP-1 ( P=0.028) and an approximate 10-fold level of MMP-3 and PGE(2) release over that of HACs, each being stimulated by histamine ( P=0.02 and 0.032, respectively, student's t-test). However, MMP-8, MMP-13 and TNFalpha were not detected for RSF cultures. Our results show that histamine modifies the behaviour of both HACs and RSFs in vitro, but different effects were observed for the production of specific MMPs and TNFalpha by the two cell types.

H1 and H2 histamine receptors modulate osteoclastic resorption by different pathways: evidence obtained by using receptor antagonists in a rat synchronized resorption model

We have previously postulated that mast cells (MC) may act as accessory cells in bone resorption. In this study we obtained evidence that histamine, the most abundant mediator released upon MC degranulation, is one of many factors modulating resorption. As the effect of histamine is mediated through different receptors, we tested the effects of mepyramine (1.5 mg/kg/day) and cimetidine (125 mg/kg/day), that antagonize H1 and H2 receptors, respectively. These effects were assessed morphometrically in a well-defined rat model of synchronized resorption at different stages of the process. On day 4 after induction (i.e., at the peak of resorption in this model), both agents reduced resorption significantly. Mepyramine acted by disturbing osteoclast activation and by reducing osteoclast activity (P < 0.01), while cimetidine principally reduced the size of the osteoclast population (P < 0.01). On day 6 (stage of declining resorption), the same resorption score as on day 4 was maintained in the mepyramine group, mainly through a marked increase in osteoclast activity (P < 0.01). In contrast, cimetidine continued to strongly reduce resorption (P < 0.01) and led to a further drop in the osteoclast population (P < 0.01). One day after induction, nonspecific esterase (NSE)-positive cells (putative osteoclast precursors) were significantly less numerous after treatment with the two agents. Significant changes in the MC population in the vicinity of the zone undergoing resorption occurred on days 4 and 6. The periosteal microvasculature adjacent to the reference bone zone was also markedly modified, especially in the cimetidine group. These results show that histamine intervenes in resorption through both H1 and H2 receptors. However, the mechanisms triggered by these receptors were quite different: H2 receptors appeared to be more strategic, as no replenishment of the osteoclast population occurred after the initial depletion in precursors. Histamine also appears to influence other neighbouring compartments, in which disturbances are probably linked to defective resorption. These findings support our hypothesis by which MC are accessory cells of resorption in this model.

A role for histamine receptors in rheumatoid arthritis

Although neurotransmitters and various chemical mediators play an important role in the pathogenesis of rheumatoid arthritis (RA), precise underlying mechanisms have yet to be determined. Histamine is a classical mediator of inflammation and three types of receptors are known. We investigated the presence and functions of histamine receptors of lymphocytes, bone marrow cells, synovial fibroblasts, and chondrocytes in experimentally-induced arthritis and human RA. The function of H2 receptors in peripheral blood lymphocytes and bone marrow cells were down regulated as measured by increments of intracellular cAMP and IL-6 production. Synovial fibroblasts from RA patients did not respond to H2 agonist to synthesize hyaluronic acid. It is evident that H2 receptors are down-regulated in lymphocytes, bone marrow cells, and synovial fibroblasts. The reduced function of H2 receptors in collagen-induced arthritis was normalized by transfer of the receptor-bearing lymphocytes and bone marrow cells. These data suggest that histamine is involved in the pathogenesis of RA.

Histamine-stimulated production of matrix metalloproteinase 1 by human rheumatoid synovial fibroblasts is mediated by histamine H1-receptors

The purpose of this study was to investigate the role of histamine in human rheumatoid synovial fibroblasts in the production of factors responsible for tissue remodelling and cartilage breakdown in rheumatoid arthritis. We examined the effects of histamine of tritiated thymidine incorporation, production of matrix metalloproteinase-1 (MMP-1), histamine H1-receptor expression, phosphoinositide metabolism and intracellular calcium ion concentration ([Ca2+]i) in human rheumatoid synovial fibroblasts. Tritiated thymidine incorporation studies demonstrated that histamine markedly stimulated the proliferation of rheumatoid synovial fibroblasts. Immunofluorescence and Northern blot analyses revealed that proMMP-1 production was also stimulated by histamine. The levels of inositol phosphates and [Ca2+]i in the cells were elevated in response to histamine, indicating that the cells expressed histamine H1-receptors; and Northern blot analysis indicated that these H1-receptors were up-regulated by histamine. In in situ hybridization, large amounts of histamine H1-receptor mRNA were also detected in rheumatoid synovial tissue. These results suggest that the interaction between H1-receptor expression in rheumatoid synovial fibroblasts and histamine secretion by mast cells and macrophages in the affected sites is an important event responsible for tissue remodelling and joint destruction in rheumatoid arthritis.

Histamine enhances interleukin (IL)-1-induced IL-1 gene expression and protein synthesis via H2 receptors in peripheral blood mononuclear cells. Comparison with IL-1 receptor antagonist

Histamine and IL-1 have been implicated in the pathogenesis of chronic inflammatory diseases, such as pulmonary allergic reactions and rheumatoid arthritis. We therefore investigated whether histamine modulated the synthesis of IL-1 beta. Human PBMC were stimulated with IL-1 alpha (10 ng/ml) in the absence or presence of histamine (10(-9)-10(-4) M). Histamine alone did not induce protein synthesis or mRNA accumulation for IL-1 beta. IL-1 alpha-induced IL-1 beta synthesis was enhanced two to threefold by histamine concentrations from 10(-6)-10(-4) M. Cimetidine, an H2 receptor antagonist, reversed the histamine (10(-5) M)-mediated increase in IL-1 alpha-induced IL-1 beta synthesis. Diphenhydramine, an H1 receptor antagonist, had no effect. Indomethacin, a cyclooxygenase inhibitor, significantly reduced IL-1 alpha-induced IL-1 beta synthesis, but had no effect on the histamine-mediated increase in IL-1 alpha-induced IL-1 beta synthesis. Histamine (10(-5) M) enhanced and sustained IL-1 beta mRNA levels in IL-1 alpha-stimulated PBMC. However, histamine reduced IL-1 beta mRNA half-life (2.4 vs 1.2 h), suggesting that histamine enhances IL-1 alpha-induced IL-1 beta synthesis at the level of transcriptional activation. On the other hand, histamine (10(-5) M) did not affect IL-1 alpha-induced synthesis of IL-1 receptor antagonist. These results suggest that mast cells may sustain chronic inflammatory processes by upregulating self-induction of IL-1 through histamine release.

IgE antibodies specific for cartilage collagens type II, IX and XI in rheumatic diseases

Serum samples from 149 patients with RA and other rheumatological diseases, and 57 non-arthritic controls have been assayed for IgE antibodies to the cartilage collagen types II, IX and XI in their native and denatured state. Using an improved ELISA technique together with antigen-binding inhibition studies to confirm specificity, 10 of the 149 (7%) patients showed IgE antibodies to human collagen type II and bovine collagen types II, IX or XI. Some patients responded to only one collagen type whereas others had IgE positive responses to two or all three collagen species. Most of the IgE responses detected were directed towards the denatured collagens. Those sera showing an IgE response to bovine type II collagen produced a similar response to the human equivalent, including two patients with SLE. None of 57 control subjects demonstrated IgE specificity for any of the cartilage collagens. Patients with IgE specificity for the cartilage collagens did not demonstrate IgM or IgA specificity for these antigens, but two of these patients showed IgG responses to type II and XI collagens. Whereas eight patients were exclusively IgE-positive for the cartilage collagens, others expressed specificities for IgG, IgM or IgA. It therefore appears that the specific autoimmune profile for each patient is often different from others, both in terms of the class of immunoglobulin expressed and the collagen antigens recognised. At present no correlations were observed between the IgE-positive patients and their clinical assessment and/or prognosis.

Production of prostaglandin E2 induced by histamine by cloned rheumatoid synovial cells

Production of prostaglandin E2, with or without histamine stimulation, by three different types of cloned rheumatoid synovial cells (macrophage like, dendritic, and fibroblast like) was evaluated. The ability of these cloned cells to respond to histamine on a cell to cell basis was as follows: macrophage like cells responded most strongly, followed by dendritic cells, followed by fibroblast like cells. Production of prostaglandin E2, stimulated by histamine, may have a role in bony destruction in rheumatoid joints.

Molecular and cellular analysis of histamine H1 receptors on cultured smooth muscle cells

Histamine is an important mediator of immediate hypersensitivity for both animals and humans. The action of histamine on target tissues is believed to be mediated by specific cell surface receptors, especially H1 and H2 receptors for hypersensitivity and inflammatory reactions, which involve stimulation of smooth muscle contractility, alterations in vascular permeability, and modifications in the activities of macrophages and lymphocytes. Although the nature of histamine receptors in the brain and peripheral tissues has been studied extensively by many laboratories, the molecular mechanism of histamine receptor-mediated reactions is not fully understood, mainly because histamine receptors are incompletely characterized from the biochemical point of view. In previous studies, we have found that the cultured smooth muscle cell line DDT1MF-2, derived from hamster vas deferens, expresses low-affinity histamine H1 receptors and responds biochemically and functionally to H1-specific stimulation (Mitsuhashi and Payan, J Cell Physiol 134:367, 1988). This cell line provides a model for analyzing the biochemical responses of H1 receptor-mediated reactions in peripheral tissues. In this review, we summarized our recent progress in the study of low-affinity H1 receptors on DDT1MF-2 cells.

Anti-inflammatory drugs modulate histamine release from mast cells induced by fibrinogen degradation products

The products resulting from proteolytic degradation of human fibrinogen (FDP) were found to induce the release of histamine from rat peritoneal mast cells. Low molecular weight, dialysable peptides (FDP) showed the highest dose dependent, histamine releasing activity. Histamine release induced by FDP was effectively inhibited by the gold compound auranofin at a concentration of 10(-5)-10(-7) mol/l and also by the non-steroidal anti-inflammatory drugs BW 755c, timegadine, medosan, naproxen, and aspirin at the higher concentration range of 10(-4)-10(-6) mol/l. It is concluded that the release of histamine from mast cells may be modulated to some extent by anti-inflammatory drugs, especially auranofin, BW 755c and timegadine, a functional property which may be beneficial in the management of joint disease.

Effect of recombinant cytokines on glycolysis and fructose 2,6-bisphosphate in rheumatoid synovial cells in vitro

Recombinant-derived human interleukin 1 (IL1) alpha and beta and interferon gamma (IFN-gamma) each produced similar increases in rheumatoid synovial cell (RSC) glycolysis, as judged by increased values for glucose uptake, lactate production and cellular fructose 2,6-bisphosphate [Fru(2,6)P2]. Measurement of Fru(2,6)P2 proved to be the most sensitive parameter for an assessment of glycolysis: IL1 alpha, IL1 beta and IFN-gamma all produced a 3-6-fold increase in this metabolite whereas tumour necrosis factor (TNF alpha) was far less effective. Prostaglandin E production was stimulated predominantly by IL1 alpha and IL1 beta rather than by IFN-gamma or TNF alpha. When combinations of cytokines were examined the addition of IFN-gamma with either IL1 alpha, IL1 beta or murine IL1 produced a synergistic increase in cellular Fru(2,6)P2. The three forms of IL1 increased Fru(2,6)P2 via the same pathway, whereas IFN-gamma acted via a different mechanism. The increase in Fru(2,6)P2 in subcultured RSC produced by addition of medium from a primary culture exceeded the maximal effects of any of the single cytokines studied, suggesting the presence of a mixture of cytokines in the primary RSC culture medium.

Evidence for both histamine H1 and H2 receptors on human articular chondrocytes

Using specific histamine H1 and H2 receptor antagonists, evidence is presented for the existence of both H1 and H2 receptors on human articular chondrocytes in vitro. Stimulation of the H1 receptor by histamine (range 0.18 to 17.8 mumol/l) significantly increased prostaglandin E (PGE) production, while activation of the histamine H2 receptor increased intracellular cyclic adenosine-5'-monophosphate (AMP). The histamine H1 antagonists mepyramine and tripelennamine blocked the histamine induced increase in PGE production, and the H2 antagonists cimetidine and ranitidine prevented the increase in intracellular cyclic AMP. These observations suggest that mast cell-chondrocyte interactions mediated via histamine may contribute to some of the pathophysiological changes observed in joint disease.