Macl-GPIb alpha Interaction Library

The library developed by ChemDiv contains 22.214 compounds targeting the Mac-1-GPIb alpha interaction.

Leukocyte-platelet interaction plays a crucial role in mediating leukocyte adhesion to thrombi and leukocyte recruitment to sites of vascular injury. This interaction is facilitated by β2-integrin Mac-1 (also known as integrin αMβ2) and its counter-receptor on platelets, glycoprotein Ibα (GPIb), which is a component of the GP Ib-IX-V complex, the platelet von Willebrand factor (vWf) receptor [1].

Studies have shown that the Mac-1-GPIbα interaction involves the Mac-1 I domain (homologous to the vWf A1 domain), as well as the GPIb leucine-rich repeat and COOH-terminal flanking regions. Since leukocyte–platelet interactions bidirectionally induce signals that amplify pro-inflammatory and pro-thrombotic cellular responses, they present a molecular target for disrupting leukocyte-platelet complexes. This disruption is important in addressing vascular inflammation in conditions such as thrombosis, atherosclerosis, and angioplasty-related restenosis [2].

Currently available anti-thrombotic drugs, including antiplatelet agents and anticoagulants, are associated with a significant bleeding risk and increased mortality. Numerous research studies have demonstrated that small-molecule inhibitors targeting the Mac-1-GPIb interaction can successfully inhibit thrombosis. Furthermore, it has been identified that targeting this interaction offers anti-thrombotic therapeutic potential with a reduced risk of bleeding [1].

The mechanism of action of Mac-1-GPIb inhibitors was discovered to be rooted in their ability to selectively disrupt this specific interaction between Mac-1 and the GPIb alpha domain. These inhibitors function by binding to the Mac-1 I domain, a region critical for the interaction with GPIb. This binding effectively blocks the adhesion of leukocytes to platelets, a key step in the formation of thrombi and the progression of inflammatory vascular diseases. By targeting this precise interaction, these inhibitors can prevent the bidirectional signaling cascade that typically amplifies inflammatory and thrombotic responses in vascular tissues. Furthermore, unlike broad-spectrum antiplatelet or anticoagulant therapies, Mac-1-GPIb inhibitors offer a more targeted approach, potentially reducing the risk of bleeding complications. This specificity is particularly advantageous in the context of drug discovery, as it allows for the development of therapeutics that can effectively mitigate thrombotic risks while minimizing unwanted side effects.

References

[1] Y. Wang et al., “Leukocyte integrin Mac-1 regulates thrombosis via interaction with platelet GPIbα,” Nat. Commun., vol. 8, no. May, 2017, doi: 10.1038/ncomms15559.

[2] D. I. Simon et al., “Platelet glycoprotein Ibα is a counterreceptor for the leukocyte integrin Mac-1 (CD11b/CD18),” J. Exp. Med., vol. 192, no. 2, pp. 193–204, 2000, doi: 10.1084/jem.192.2.193.