Discovery and Development of First-in-Class ACKR3/CXCR7 Superagonists for Platelet Degranulation Modulation

Abstract

The atypical chemokine receptor 3 (ACKR3), formerly known as CXC-chemokine receptor 7 (CXCR7), has been postulated to regulate platelet function and thrombus formation. Herein, we report the discovery and development of first-in-class ACKR3 agonists, which demonstrated superagonistic properties with E max values of up to 160% compared to the endogenous reference ligand CXCL12 in a β-arrestin recruitment assay. Initial in silico screening using an ACKR3 homology model identified two hits, C10 (EC50 19.1 μM) and C11 (EC50 = 11.4 μM). Based on these hits, extensive structure-activity relationship studies were conducted by synthesis and testing of derivatives. It resulted in the identification of the novel thiadiazolopyrimidinone-based compounds 26 (LN5972, EC50 = 3.4 μM) and 27 (LN6023, EC50 = 3.5 μM). These compounds are selective for ACKR3 versus CXCR4 and show metabolic stability. In a platelet degranulation assay, these agonists effectively reduced P-selectin expression by up to 97%, suggesting potential candidates for the treatment of platelet-mediated thrombosis.

Design, synthesis and pharmacological characterization of the first photoswitchable small-molecule agonist for the Atypical Chemokine Receptor 3

“…S9), indeed losing the ability to bind ACKR3. The bulkier substituent of trans- 3g (pEC50 = NA) at the terminal aryl ring would not fit optimally in P I, clashing with Y51 1 39 . or losing the optimal ligand conformation to fit P I (Fig.…”

Pharmacological characterization and radiolabeling of VUF15485, a high-affinity small-molecule agonist for the atypical chemokine receptor ACKR3

“…From kinetic association and dissociation experiments it can be determined that In general, radioligand or fluorescence-based binding studies are key in drug discovery as they allow the accurate determination of equilibrium binding affinity constants and/or the kinetics of binding of GPCR ligands (Bayrak et al, 2022, Hopkins et al, 2022, Richard-Bildstein et al, 2020, Wijtmans et al, 2012a. Moreover, huge progress in the field of ACKR3 biochemistry has enabled NMR approaches with 13 CH3-e-methionine labelled ACKR3 and the elucidation of cryo-EM structures of antibody-stabilized ACKR3 with CXCL12, a CXCL12 analog and the ACKR3 agonist CCX662 (Kleist et al, 2022, Yen et al, 2022.…”

New pairings and deorphanization among the atypical chemokine receptor family — physiological and clinical relevance

“…However, considering the importance and multiplicity of their functions, the constantly growing number of ligands identified, the complexity of their biology and the interconnectivity with multiple systems, the targeting of ACKRs remains a great challenge. So far, only small molecules, peptides, modified chemokines and antibody fragments targeting ACKR3 have been reported, partly owing to the long-established importance of the CXCR4-CXCL12 axis in cancer, autoimmune and cardiovascular diseases (13,70,119,120,(127)(128)(129)(130)(131). Nevertheless, the increasing number of studies showing implication of other ACKRs, including ACKR5, in cancer development, progression but also protection together with the increasing availability of screening assays specific for each ACKR will likely favor in the new future the development of modulators for other members of the family (100,122).…”