Glutathione disrupts galectin-10 Charcot-Leyden crystal formation to possibly ameliorate eosinophil-based diseases such as asthma

Abstract

Charcot-Leyden crystals (CLCs) are the hallmark of many eosinophilic-based diseases, such as asthma. Here, we report that reduced glutathione (GSH) disrupts CLCs and inhibits crystallization of human galectin-10 (Gal-10). GSH has no effect on CLCs from monkeys ( Macaca fascicularis or M. mulatta ), even though monkey Gal-10s contain Cys29 and Cys32. Interestingly, human Gal-10 contains another cysteine residue (Cys57). Because GSH cannot disrupt CLCs formed by the human Gal-10 variant C57A or inhibit its crystallization, the effects of GSH on human Gal-10 or CLCs most likely occur by chemical modification of Cys57. We further report the crystal structures of Gal-10 from M . fascicularis and M . mulatta , along with their ability to bind to lactose and inhibit erythrocyte agglutination. Structural comparison with human Gal-10 shows that Cys57 and Gln75 within the ligand binding site are responsible for the loss of lactose binding. Pull-down experiments and mass spectrometry show that human Gal-10 interacts with tubulin α-1B, with GSH, GTP and Mg 2+ stabilizing this interaction and colchicine inhibiting it. Overall, this study enhances our understanding of Gal-10 function and CLC formation and suggests that GSH may be used as a pharmaceutical agent to ameliorate CLC-induced diseases.

The Role of Galectins in Asthma Pathophysiology: A Comprehensive Review

“…Nevertheless, the administration of CLCs in mice can induce monocyte/macrophages, dendritic cells, and neutrophils proliferation via TNF-α, IL-1β, and IL-6 production [43]. Interestingly, while molecules like lactose or galactose can induce the development of CLCs through an electrostatic potential shift during Gal-10 dimerization [44], Glutathione appears to inhibit the formation of CLCs in animal models, binding the CRD of CLCs and preventing Gal-10 crystallization [45]. However, apart from its release after crystallization, Gal-10 can also form eosinophil extracellular traps (EETs) along with histone-rich DNA and other cytoplasmic proteins from secondary granules, being secreted by active eosinophils or after their cytolysis (ETosis) [84,85].…”