Identification of a Potent and Orally Active Non-peptide C5a Receptor Antagonist

Sumichika, Hiroshi; Sakata, Kiyomi; Sato, Noriko; Takeshita, Sanae; Ishibuchi, Seigo; Nakamura, Masashi; Kamahori, Takao; Ehara, Syuji; Itoh, Katsuhiko; Ohtsuka, Tatsuyuki; Ohbora, Tomoko; Mishina, Tadashi; Komatsu, Hidetada; Naka, Yoichi

doi:10.1074/jbc.m209672200

Cited by 88 publications

(71 citation statements)

References 53 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As it has been shown that C5aRa (W54011) had no effect on the induction of Ca 2ϩ influx in mouse neutrophils (19) to further clarify W54011 has effect on DC functional modulation, we compared ϩ T cells. T cell proliferation was assessed by thymidine uptake at 72 h and IFN-␥ production was measured at day 5 by ELISA.…”

Section: Blockade Of C5ar Lowers DC Activation Phenotype and Allostimmentioning

confidence: 99%

Dendritic Cell Function in Allostimulation Is Modulated by C5aR Signaling

Peng

Wang

et al. 2009

The Journal of Immunology

106

103

View full text Add to dashboard Cite

Regulation of T cell immunity by C5a has been suggested from recent studies. However, the underlying mechanisms, particularly the involved cells and biochemical basis, are not well defined. In this study, the direct modulation of dendritic cell (DC) activation and its function in T cell stimulation by C5a-C5aR interaction and the involved signaling pathways were investigated. We show that DCs from C5aR−/− mice and normal DCs treated with C5aR antagonist have less-activated phenotype characterized with increased IL-10 and decreased IL-12p70 production in response to LPS stimulation, lowered surface expression of MHC class II, B7.2, and consequently have reduced capacity to stimulate allospecific T cells. Conversely, C5a stimulation up-regulates DC activation and its function in allostimulation. Furthermore, stimulation of C5aR mediates the inhibition of cAMP production and protein kinase A activity and is involved in activation of PI3K/AKT and NF-κB signaling in DCs. These results demonstrate that C5a acts directly on C5aR expressed on DCs resulting in the cell activation and subsequently enhances its capacity for allospecific T cell stimulation. It also suggests that NF-κB signaling induced by down-regulation of cAMP/ protein kinase A pathway and up-regulation of PI3K/AKT pathway following C5a stimulation may contribute to up-regulation of DC function.

show abstract

Section: Blockade Of C5ar Lowers DC Activation Phenotype and Allostimmentioning

confidence: 99%

Dendritic Cell Function in Allostimulation Is Modulated by C5aR Signaling

Peng

Wang

et al. 2009

The Journal of Immunology

106

103

View full text Add to dashboard Cite

show abstract

“…Several antagonists for CD88 have been described, including peptides (20 -22), a nonpeptidic compound (23), C5a mutants (24 -26), and anti-C5aR antibodies (27,28). All of these compounds are potent CD88 antagonists in vitro; however, only the C5a mutants C5aRAM (24) and jun/fos-A8 (25), the cyclic peptide AcPhe[L-ornithinePro-D-cyclohexylalanine-Trp-Arg] (AcF-(OpdChaWR)) (29), and a nonpeptidic antagonist (23) have been proven useful in vivo. Administration of these inhibitors protects animals from in-flammatory responses in immune complex disease (25,29,30), ischemia/reperfusion injury (25,31,32), and C5a-induced neutropenia (23,24).…”

mentioning

confidence: 99%

“…All of these molecules are potent C5aRA for human CD88; however, only the C5a mutant jun/fos-A8 is also a potent antagonist for mouse, rat, and guinea pig CD88. C5aRAM acts as an antagonist for rabbit and micropig CD88 (24), AcF-(OpdChaWR) acts as an antagonist for rat and dog CD88 (29), and the nonpeptidic compound acts as an antagonist for gerbil and cynomolgus monkey CD88 (23).…”

mentioning

confidence: 99%

C5a Mutants Are Potent Antagonists of the C5a Receptor (CD88) and of C5L2

Otto

Hawlisch

Monk

et al. 2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

The anaphylatoxin C5a exerts a plethora of biologic activities critical in the pathogenesis of systemic inflammatory diseases. Recently, we reported on a C5a mutant, jun/fos-A8, as a potent antagonist for the human and mouse C5a receptor (CD88). Addressing the molecular mechanism accounting for CD88 receptor antagonism by site-directed mutagenesis, we found that a positively charged amino acid at position 69 is crucial. Replacements by either hydrophobic or negatively charged amino acids switched the CD88 antagonist jun/fos-A8 to a CD88 agonist. In addition to CD88, the seven-transmembrane receptor C5L2 has recently been found to provide high affinity binding sites for C5a and its desarginated form, C5adesArg 74 . A jun/fos-A8 mutant in which the jun/ fos moieties and amino acids at positions 71-73 were deleted, A8 ⌬71-73 , blocked C5a and C5adesArg 74 binding to CD88 and C5L2. In contrast, the cyclic C5a C-terminal analog peptide AcF-[OP-D-ChaWR] inhibited binding of the two anaphylatoxins to CD88 but not to C5L2, suggesting that the C5a core segment is important for high affinity binding to C5L2. Both receptors are coexpressed on human monocytes and the human mast cell line HMC-1; however, C5L2 expression on monocytes is weaker as compared with HMC-1 cells and highly variable. In contrast, no C5L2 expression was found on human neutrophils. A8 ⌬71-73 is the first antagonist that blocks C5a and C5adesArg 74 binding to both C5a receptors, CD88 and C5L2, making it a valuable tool for studying C5L2 functions and for blocking the biological activities of C5a and C5adesArg 74 in mice and humans.

show abstract

“…However, cellbased assays have reported that W-54011 is unable to block C5a-driven Ca 2+ mobilisation in polymorphonuclear leukocytesof rodents and select other mammals therefore it is possible that in vivo efficacy of this compound is unlikely (Sumichika et al, 2002). W-54011 is the only alternative small molecule C5ar1 antagonist commercially available therefore it was still deemed appropriate to test for in vivo efficacy to attempt to corroborate the in vitro results in a poorly understood in vivo disease situation.…”

Section: B Dmentioning

confidence: 99%

“…A summary adapted from Holland et al (2004) is given in Table 1 which outlines the animal models in which PMX53 has been tested. Additional compounds utilised in this thesis to modulate actions of C5ar1 not related to PMX53 in structure include the non-selective agonist EP54, which has been shown to also bind and activate C3ar, an anaphylatoxin receptor upstream in the complement cascade (Scully et al, 2010) and W-54011, an alternative non-peptide antagonist of C5a receptors (Sumichika et al, 2002).…”

Section: B Dmentioning

confidence: 99%

The role of complement in epilepsy: a specific focus on C5ar1 and its role in seizure initiation and disease development

Benson¹

View full text Add to dashboard Cite

Neuroinflammation and its role in seizure initiation and epilepsy disease development is being investigated, specifically the role of innate immune complement activation through the C5a receptor, C5ar1.C5ar1 expression was found to be significantly upregulated during epilepsy disease progression in several experimental mouse models, in addition to other complement components such as C3, the precursor to C5a. Building upon existing studies supporting the role of inflammation and other complement components in epilepsy, this finding indicates a contribution of C5a and complement activation in this disease. This lead to creation of the primary hypothesis of this thesis; inhibition of C5ar1 activation is potentially neuroprotective and anticonvulsant in epilepsy.To test this hypothesis a small peptide antagonist of C5ar1, PMX53, was used. It was shown to be anticonvulsant in two acute and two chronic seizure models. PMX53 increased the seizure threshold significantly in both the 6Hz test and the corneal kindling model, as well as reduced EEG seizure power in the pilocarpine-induced SE model, indicating anticonvulsant actions. Studies using the chronic intrahippocampal kainate model combined with EEG, showed that PMX53 was acutely anticonvulsant after a single peripheral administration, significantly reducing total time in seizure by >50% as well as EEG seizure power. In addition, treatment of mice with PMX53 during pilocarpine-SE lead to a vast reduction in EEG seizure power highlighting further anticonvulsant effects. These results suggest inhibition of C5ar1 is beneficial in increasing seizure thresholds in several mouse models of epilepsy.Further studies using inert structural analogues of PMX53 and C5ar1-deficient mice in the 6Hz model showed that PMX53's anticonvulsant effect is C5ar1-dependent. This confirms my hypothesis that antagonism of C5ar1 is anticonvulsant. To determine if C5ar1-mediated anticonvulsant effects lead to changes in subsequent cellular damage, neuronal cell death in the hippocampal formation was evaluated acutely after pilocarpine-induced SE. In both PMX53-treated animals and mice lacking the C5ar1 receptor, significant reductions in neuronal degeneration and loss were evident in key hippocampal areas including CA1 and CA3 pyramidal cell layers.iii In addition, the explicit role of C5ar1 expression on microglial cells was investigated, given that consistent upregulation of the receptor was shown at varying stages post-epileptic insult in mice. Specifically microglial activation phenotypes were assessed, based on expression patterns of inflammatory and activation markers. M1 phenotype is considered to be more inflammatory in nature and is detected through expression of pro-inflammatory cytokines, i.e. IL-1β, TNFα, IL-6 and classical activation markers, i.e. CD16, CD86. M2 phenotype is defined as being more reparative in nature, with markers such as Arginase1 (Arg1) and Chitinase-like-3 (Ym1) being associated with this phenotype, all linked to different aspects of cell repair, as wel...

show abstract

Identification of a Potent and Orally Active Non-peptide C5a Receptor Antagonist

Abstract: The anaphylatoxin C5a is a potent chemotactic factor for neutrophils and other leukocytes, and functions as an important inflammatory mediator. Through a high capacity screening followed by chemical optimization,

Cited by 88 publications

References 53 publications

Dendritic Cell Function in Allostimulation Is Modulated by C5aR Signaling

Dendritic Cell Function in Allostimulation Is Modulated by C5aR Signaling

C5a Mutants Are Potent Antagonists of the C5a Receptor (CD88) and of C5L2

The role of complement in epilepsy: a specific focus on C5ar1 and its role in seizure initiation and disease development

Contact Info

Product

Resources

About