POS0442 GLPG4399: SELECTIVE SIK3 INHIBITION AS A NOVEL MODE OF ACTION FOR THE TREATMENT OF INFLAMMATORY ARTHRITIC DISEASES (PRECLINICAL)

Background

Salt-inducible kinases (SIKs) is a family of kinases with immunomodulatory function identified using a proprietary adenoviral shRNA knockdown target discovery platform. Moreover, SIK inhibition has previously been shown to have a role in inflammatory signalling.1–3 These findings suggest a therapeutic potential for SIK inhibition in inflammatory indications. A medicinal chemistry effort resulted in the development of a first-in-class, oral, selective SIK3 inhibitor: GLPG4399. This compound may be beneficial in inflammatory diseases such as rheumatoid and psoriatic arthritis which are chronic disorders characterized by impaired joint synovial inflammation.

Objectives

Our research aimed to characterize GLPG4399 and explore its impact in arthritis-relevant inflammatory in vitro phenotypic cell assays, and to evaluate the therapeutic potential of selective SIK3 inhibition in in vivo experimental models of arthritis.

Methods

The selectivity and potency of GLPG4399 was profiled using biochemical and target-based cell assays. The mode of action of selective SIK3 inhibition in inflammation was explored in an in vitro panel of innate (monocytes, macrophages, dendritic cells) and adaptive (B and T lymphocytes) immune phenotypic assays and in a lipopolysaccharide (LPS)-stimulated human whole blood assay by measuring the production of inflammatory cytokines. In vivo target engagement was evaluated in an acute LPS-stimulated cytokine release mouse model by measuring plasma tumour necrosis factor (TNF) α levels. The therapeutic efficacy of GLPG4399 was evaluated in vivo in collagen-induced arthritis (CIA) and IL-23-induced psoriatic arthritis mouse models by assessing disease activity endpoints.

Results

GLPG4399 was shown to be a SIK3 inhibitor with high selectivity against a panel of 370 kinases. The wide effect of SIK3 inhibition on key immune cell types was demonstrated by GLPG4399’s reduction of pro-inflammatory cytokines produced by monocytes, macrophages, dendritic cells, B and T lymphocytes in a panel of in vitro innate and adaptive immune phenotypic assays. The biological activity and target engagement of GLPG4399 was further demonstrated by dose-dependent inhibition of TNFα production in vitro in LPS-stimulated human whole blood and in vivo in the blood of LPS-challenged mice. Oral treatment with GLPG4399 in mice resulted in a significant and dose-dependent improvement of disease activity score in both CIA and the psoriatic arthritis disease model. Moreover, bone erosion in CIA and new bone formation in the psoriatic arthritis disease model were significantly reduced.

Conclusion

Our preclinical findings demonstrate the strong immunomodulatory effect of SIK3 inhibition in arthritis-relevant inflammatory cell assays and highlight the significant preclinical efficacy of GLPG4399 in two experimental arthritis mouse models. The novel mechanisms of action of GLPG4399 represents a promising approach for the treatment of arthritis.

References

[1]Sundberg TB et al. PNAS 2014;111:12468–73.

[2]Lombardi MS et al. J Leukoc Biol 2016;99:711–21.

[3]Wein MN et al. Trends Endocrinol Metab 2018;29:723–35.

Acknowledgements

These studies were funded by Galapagos NV (Mechelen, Belgium). Editorial and publications management support was provided by PharmaGenesis London, London, UK, and funded by Galapagos NV.

Disclosure of Interests

Stephanie Lavazais Employee of: Employee of Galapagos., Anna Pereira-Fernandes Employee of: Employee of Galapagos., Carole Delachaume Employee of: Employee of Galapagos., Catherine Jagerschmidt Employee of: Employee of Galapagos., Michael Drennan Employee of: Employee of Galapagos., Didier Merciris Employee of: Employee of Galapagos., Christophe Peixoto Employee of: Employee of Galapagos., Monica Borgonovi Employee of: Employee of Galapagos., Nicolas Desroy Employee of: Employee of Galapagos., David Amantini Employee of: Employee of Galapagos., Steve De Vos Employee of: Employee of Galapagos., Kris Nys Employee of: Employee of Galapagos.

In Vitro Heme Coordination of a Dye-Decolorizing Peroxidase-The Interplay of Key Amino Acids, pH, Buffer and Glycerol

Dye-decolorizing peroxidases (DyPs) have gained interest for their ability to oxidize anthraquinone-derived dyes and lignin model compounds. Spectroscopic techniques, such as electron paramagnetic resonance and optical absorption spectroscopy, provide main tools to study how the enzymatic function is linked to the heme-pocket architecture, provided the experimental conditions are carefully chosen. Here, these techniques are used to investigate the effect of active site perturbations on the structure of ferric P-class DyP from Klebsiella pneumoniae (KpDyP) and three variants of the main distal residues (D143A, R232A and D143A/R232A). Arg-232 is found to be important for maintaining the heme distal architecture and essential to facilitate an alkaline transition. The latter is promoted in absence of Asp-143. Furthermore, the non-innocent effect of the buffer choice and addition of the cryoprotectant glycerol is shown. However, while unavoidable or indiscriminate experimental conditions are pitfalls, careful comparison of the effects of different exogenous molecules on the electronic structure and spin state of the heme iron contains information about the inherent flexibility of the heme pocket. The interplay between structural flexibility, key amino acids, pH, temperature, buffer and glycerol during in vitro spectroscopic studies is discussed with respect to the poor peroxidase activity of bacterial P-class DyPs.

Copper(II) Complexes of Sulfonated Salan Ligands: Thermodynamic and Spectroscopic Features and Applications for Catalysis of the Henry Reaction

Copper(II) complexes formed with sulfonated salan ligands (HSS) have been synthesized, and their coordination chemistry has been characterized using pH-potentiometry and spectroscopic methods [UV-vis, electron paramagnetic resonance (EPR), and electron-electron double resonance (ELDOR)-detected NMR (EDNMR)] in aqueous solution. Several bridging moieties between the two salicylamine functions were introduced, e.g., ethyl (HSS), propyl (PrHSS), butyl (BuHSS), cyclohexyl (cis-CyHSS, trans-CyHSS), and diphenyl (dPhHSS). All of the investigated ligands feature excellent copper(II) binding ability via the formation of a (O^-,N,N,O^-) chelate system. The results indicated that the cyclohexyl moiety significantly enhances the stability of the copper(II) complexes. EPR studies revealed that the arrangement of the coordinated donor atoms is more symmetrical around the copper(II) center and similar for HSS, BuHSS, CyHSS, and dPhHSS, respectively, and a higher rhombicity of the g tensor was detected for PrHSS. The copper(II) complexes of the sulfosalan ligands were isolated in solid form also and showed moderate catalytic activity in the Henry (nitroaldol) reaction of aldehydes and nitromethane. The best yield for nitroaldol production was obtained for copper(II) complexes of PrHSS and BuHSS, although their metal binding ability is moderate compared to that of the cyclohexyl counterparts. However, these complexes possess larger spin density on the nitrogen nuclei than that for the other cases, which alters their catalytic activity.

Crystal structures of zinc(II) complexes with β-hydroxypyridinecarboxylate ligands: examples of structure-directing effects used in inorganic crystal engineering

The coordination properties of four hydroxypyridinecarboxylates, designed for the treatment of iron-overloading conditions as bidentate O,O'-donor ligands, have been studied with ZnII in the solid state. The coordination compounds [Zn(A1)2(H2O)2] (1), [Zn(A2)2(H2O)] (2), [Zn(A3)2(H2O)]·2H2O (3) and [Zn2(B1)4(H2O)2]·4H2O (4), where the ligands are 1-methyl-4-oxidopyridinium-3-carboxylate (A1, C7H6NO3), 1,6-dimethyl-4-oxidopyridinium-3-carboxylate (A2, C8H8NO3), 1,5-dimethyl-4-oxido-pyridinium-3-carboxylate (A3, C8H8NO3) and 1-methyl-3-oxidopyridinium-4-carboxylate (B1, C7H6NO3), have been synthesized and analysed by single-crystal X-ray diffraction. The ligands were chosen to probe (i) the electronic effects of inverting the positions of the O-atom donor groups (i.e. A1 versus B1) and (ii) the electronic and steric effects of the addition of a second methyl group in different positions on the pyridine ring. Two axially coordinated water molecules resulting in a six-coordinated symmetrical octahedron complement the bis-ligand complex of A1. Ligands A2 and A3 form five-coordinated trigonal bipyramidal complexes with one additional water molecule in the coordination sphere, which is a rarely reported geometry for ZnII complexes. Ligand B1 shows a dimeric structure, where the two Zn2+ dications have slightly distorted octahedral geometry and the pyridinolate O atom of the neighbouring complex bridges them. The coordination spheres of the Zn2+ dications and the supramolecular structures are discussed in detail. The packing arrangements of 1-3 are similar, having alternating hydrophilic and hydrophobic layers, however the similarity is broken in 4. The obtained coordination geometries are compared with their previously determined CuII analogues. The study of the individual complexes is complemented with a comprehensive analysis of ZnII complexes with oxygen donor ligands with data from the Cambridge Structural Database.

On the Track of Long-Range Electron Transfer in B-Type Dye-Decolorizing Peroxidases: Identification of a Tyrosyl Radical by Computational Prediction and Electron Paramagnetic Resonance Spectroscopy

The catalytic activity of dye-decolorizing peroxidases (DyPs) toward bulky substrates, including anthraquinone dyes, phenolic lignin model compounds, or 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), is in strong contrast to their sterically restrictive active site. In two of the three known subfamilies (A- and C/D-type DyPs), catalytic protein radicals at surface-exposed sites, which are connected to the heme cofactor by electron transfer path(s), have been identified. So far in B-type DyPs, there has been no evidence for protein radical formation after activation by hydrogen peroxide. Interestingly, B-type Klebsiella pneumoniae dye-decolorizing peroxidase (KpDyP) displays a persistent organic radical in the resting state composed of two species that can be distinguished by W-band electron spin echo electron paramagnetic resonance (EPR) spectroscopy. Here, on the basis of a comprehensive mutational and EPR study of computationally predicted tyrosine and tryptophan variants of KpDyP, we demonstrate the formation of tyrosyl radicals (Y247 and Y92) and a radical-stabilizing Y-W dyad between Y247 and W18 in KpDyP, which are unique to enterobacterial B-type DyPs. Y247 is connected to Y92 by a hydrogen bonding network, is solvent accessible in simulations, and is involved in ABTS oxidation. This suggests the existence of long-range electron path(s) in B-type DyPs. The mechanistic and physiological relevance of the reaction mechanism of B-type DyPs is discussed.

Surprising differences in the respiratory protein of insects: A spectroscopic study of haemoglobin from the European honeybee and the malaria mosquito

Only recently it was discovered that haemoglobin (Hb) belongs to the standard gene repertoire of insects, although their tracheal system is used for respiration. A classical oxygen-carrying function of Hb is only obvious for hexapods living in hypoxic environments. In other insect species, including the common fruit fly Drosophila melanogaster, the physiological role of Hb is yet unclear. Here, we study recombinant haemoglobin from the European honeybee Apis mellifera (Ame) and the malaria mosquito Anopheles gambiae (Aga). Spectroscopic evidence shows that both proteins can be classified as hexacoordinate Hbs with a strong affinity for the distal histidine. AgaHb1 is proposed to play a role in oxygen transport or sensing based on its multimeric state, slow autoxidation, and small but significant amount of five-coordinated haem in the deoxy ferrous form. AmeHb appears to behave more like vertebrate neuroglobin with a complex function given its diversified distribution in the genome.

Roles of distal aspartate and arginine of B-class dye-decolorizing peroxidase in heterolytic hydrogen peroxide cleavage

Dye-decolorizing peroxidases (DyPs) represent the most recently classified hydrogen peroxide-dependent heme peroxidase family. Although widely distributed with more than 5000 annotated genes and hailed for their biotechnological potential, detailed biochemical characterization of their reaction mechanism remains limited. Here, we present the high-resolution crystal structures of WT B-class DyP from the pathogenic bacterium Klebsiella pneumoniae (KpDyP) (1.6 Å) and the variants D143A (1.3 Å), R232A (1.9 Å), and D143A/R232A (1.1 Å). We demonstrate the impact of elimination of the DyP-typical, distal residues Asp-143 and Arg-232 on (i) the spectral and redox properties, (ii) the kinetics of heterolytic cleavage of hydrogen peroxide, (iii) the formation of the low-spin cyanide complex, and (iv) the stability and reactivity of an oxoiron(IV)porphyrin π-cation radical (Compound I). Structural and functional studies reveal that the distal aspartate is responsible for deprotonation of H₂O₂ and for the poor oxidation capacity of Compound I. Elimination of the distal arginine promotes a collapse of the distal heme cavity, including blocking of one access channel and a conformational change of the catalytic aspartate. We also provide evidence of formation of an oxoiron(IV)-type Compound II in KpDyP with absorbance maxima at 418, 527, and 553 nm. In summary, a reaction mechanism of the peroxidase cycle of B-class DyPs is proposed. Our observations challenge the idea that peroxidase activity toward conventional aromatic substrates is related to the physiological roles of B-class DyPs.

EPR and DFT analysis of biologically relevant chromium(V) complexes with d-glucitol and d-glucose

1,2-diolato ligands, such as carbohydrates and glycoproteins, tend to stabilize chromium(V), thus forming important intermediates that have been implicated in the genotoxicity of Cr(VI). Since many years, room-temperature continuous-wave electron paramagnetic resonance (EPR) at X-band microwave frequencies has been used as a standard characterization tool to study chromium(V) intermediates formed during the reduction of Cr(VI) in the presence of biomolecules. In this work, the added value is tested of using a combination of pulsed and high-field EPR techniques with density functional theory computations to unravel the nature of Cr(V) complexes with biologically relevant chelators, such as carbohydrates. The study focuses on the oxidochromium(V) complexes formed during reduction of potassium dichromate with glutathione in the presence of the monosaccharide d-glucose or the polyalcohol d-glucitol. It is shown that although the presence of a multitude of Cr(V) intermediates may hamper a complete structural determination, the combined EPR and DFT approach reveals unambiguously the effect of freezing on the location of the counterions, the gradual replacement of water ligands by the diols, and the preference of Cr(V) to bind certain conformers.

Therapeutic innovations in inflammatory bowel diseases

Inflammatory bowel disease (IBD) is a spectrum of complex multifactorial immune disorders characterized by chronic inflammation of the gut. Significant advances have been made in unraveling the pathogenesis of this disease spectrum, which have spurred the discovery of new therapeutic targets and strategies. In this review, we highlight the emerging new classes of IBD therapeutics under clinical evaluation and their method of action, including JAK inhibitors, anti-SMAD7 oligonucleotides, and cell-based therapies. Moreover, we discuss how an approach based on unique molecular insights in a given patient will, in the future, lead to a truly individualized/tailored disease management, starting at diagnosis, aiding in prognosis, and resulting in a personalized therapeutic approach.

Triple Test Screening for Down Syndrome: Looking Back on a False-Positive Result and Having or Not Having a Triple Test in Subsequent Pregnancies

Objectives: It was the main aim of the present retrospective study carried out in Flanders to evaluate how women with a false-positive triple test result look back on their experience and decision making and how many of them make use of the triple test in subsequent pregnancies. Methods: All 508 women tested in the Centre for Human Genetics in Leuven in 1995 who had a positive triple test result followed by a normal amniocentesis outcome were invited to participate in a mailed questionnaire study with open and multiple choice questions in 1998. The response rate was 68%. Results: The answers to the multiple choice question assessing how they look back on their initial expectations regarding the exact meaning of the triple test revealed that less than one half reported that it concerned the identification of 'a higher risk of carrying a child with Down syndrome (DS)'. Reporting correct initial expectations was significantly associated with a higher education level. The same holds for indecisiveness regarding pregnancy termination should the amniocentesis have detected a fetus with DS. As expected, a large majority of the women reported a high level of distress or worry after the communication of the positive triple test result. Overall the findings show that retrospectively most women had the feeling that the decision to have amniocentesis was their own decision rather than a professional's. Of the subgroup with one or more subsequent pregnancies 70% had another triple test. Conclusions: The overall results of this study clearly reveal a need for a systematic approach aimed at better informing and counselling pregnant women about the implications and limitations of the triple test. Notwithstanding the reported high level of distress caused by a positive triple test result, a large majority of the women with subsequent pregnancies had another triple test; they represent a clearly higher percentage than in another recent study. Copyright 2001 S. Karger AG, Basel

Parenting stress and psychosocial well-being among parents with twins conceived naturally or by reproductive technology

This study compared parenting stress and psychosocial well-being among parents with 1 year old twins conceived in three different ways: (i) spontaneously without any medical assistance (54 families), (ii) spontaneously following hormonal treatment (25 families) and (iii) following in-vitro fertilization (IVF) or artificial insemination (AI) with the semen of the social father (24 families). The investigation included the Parenting Stress Index (PSI) and the General Health Questionnaire (GHQ-30). Since the presence of older children differed significantly between the three groups, this factor was included in the statistical analysis. Overall, no significant differences were found between the three study groups, either for the mothers or for the fathers. Nevertheless, we found a main effect of the presence of older children and an interaction effect of the presence of older children and the conception mode on some of the scales for the mothers: first-time mothers showed significantly higher stress related to parental competence, health and the partner relationship compared with mothers who had older children. First-time mothers with a history of infertility obtained significantly higher stress scores for parental competence and health and showed lower psychosocial well-being compared with naturally conceiving first-time mothers and mothers with a history of infertility who already had children.

Feelings and the need for information and counselling of expectant parents of twins

In this study, expectant parents of twins were questioned about their feelings and need for information and counselling on the parenting of twins. Data were obtained from self-rating questionnaires and an interview with the expectant mother. From the results it is argued that expectant parents of twins need specific information and counselling about the medical, emotional and parenting issues of having twins. Guidelines for organising this counselling are proposed.