Naturally occurring protein crystals play pivotal roles in numerous physiological and pathological processes [1], [2], [3], [4], [5], [6], [7], [8], [9]. Amongst these protein crystals, Charcot-Leyden crystals (CLC) primarily compose of the gal-10 protein, which is a outstanding part of human eosinophils and an indicator of eosinophil-associated irritation [10], [11], [12], [13]. Throughout eosinophil activation in inflammatory circumstances, soluble gal-10 self-assembles into distinctive bipyramidal crystals [12] (Fig. 1A). These insoluble gal-10 crystals, or CLCs, protrude from eosinophil cytoplasm, attracting inflammatory cells and triggering the discharge of proinflammatory elements in surrounding tissues [12], [14], [15]. In vivo, the crystallization of gal-10 is implicated within the growth of assorted airway ailments, together with ECRSwNP, eosinophilic bronchial asthma, and persistent eosinophilic pneumonia [16], [17], [18]. In line with the EPOS2020 suggestions, persistent rhinosinusitis (CRS) has a worldwide prevalence of as much as 12%, with ECRSwNP representing a difficult subtype marked by persistent sinonasal mucosa irritation [19]. ECRSwNP sufferers usually exhibit extreme scientific signs and a better incidence of bronchial asthma [19], [20], [21], [22]. Furthermore, ECRSwNP is much less attentive to endoscopic sinus surgical procedure, with recurrence charges exceeding 50% post-intervention [19], [20], [21], [22]. Focusing on gal-10 crystals gives a promising strategy to lowering irritation and assuaging the event of ECRSwNP and associated eosinophil-associated ailments [10]. Though anti-gal-10 monoclonal antibodies present potential in dissolving gal-10 crystals and treating gal-10-associated ailments (ARGX-118 antibody has entered Section I scientific trials), the invention of small-molecule medication with particular gal-10 crystal-targeting properties stays unattained [10]. In comparison with antibodies, small-molecule medication provide benefits by way of scalability, storage, transport, and affordability, making them a promising avenue for treating a variety of well being circumstances [23], [24].
To establish a small-molecule drug candidate for addressing gal-10 crystal-induced irritation, it’s important to find compounds able to disrupting gal-10 crystal buildings. The crystallization of gal-10 depends on advanced protein-protein interactions (PPIs) throughout three heterogeneous interfaces oriented in distinct instructions [10] (Fig. 1B). A gal-10 monomer varieties an 11-β-strand β-sandwich area composed of two antiparallel β-sheets. Gal-10 monomers pair throughout a dimerization interface I. These gal-10 dimers stack collectively and kind a macroscopic protein crystal by way of interface II, which ends from the stacking of Tyr69 and Tyr69’ facet chains, and interface III, formed by electrostatic interactions between Lys99’ and Glu10, anchored by Tyr139 [10]. Consequently, a small molecule that promotes protein-water interactions over PPIs can doubtlessly disrupt the gal-10 crystal construction. PPIs and protein solubility in aqueous options are considerably influenced by dissolved salts, significantly by means of the Hofmeister impact, the place ions play a vital position in both strengthening or weakening PPIs, thereby affecting protein meeting and solubility [25], [26], [27]. Though the Hofmeister impact has been extensively studied within the context of protein folding and aggregation, its potential to modulate pathological protein crystallization, reminiscent of gal-10, has not been explored. Impressed by the regulatory results of ions on protein solubility, we hypothesized that ions might function a chemical library for figuring out these with the potential to disrupt gal-10 crystallization. Screening ions to induce gal-10 crystal dissociation gives important data for locating a small-molecule drug to handle gal-10 crystallopathy.
On this examine, we report the invention of metformin, an FDA-approved drug, for its capability to induce the dissociation of gal-10 crystals and ameliorate gal-10 crystallization-induced lung irritation. This discovery was guided by particular ion results and achieved by means of a screening technique (Fig. 1C). We investigated the results of cations, together with tetramethylammonium ((CH3)4N+ ), ammonium (NH4+), potassium (Ok+), sodium (Na+), and guanidinium (Gdm+), and anions, together with acetate (Ac–), chloride (Cl–), and bromide (Br–), on the steadiness of gal-10 crystals in aqueous answer. This screening aimed to establish the ion with the best potential to dissolve gal-10 crystals. This strategy led us to metformin, which accommodates the potent ion Gdm+ and is acknowledged as an FDA-approved treatment. The therapeutic efficacy of metformin in treating gal-10 crystallopathy was efficiently demonstrated in an in vivo mannequin of gal-10 crystal-induced lung irritation. Metformin, probably the most generally prescription drugs globally, serves as a first-line oral treatment for sort 2 diabetes on account of its efficacy, security, and affordability. Our findings lengthen its potential past its unique medical indication, presenting a drug repurposing technique and unveiling a novel utility for metformin within the therapy of gal-10 crystallopathy.
