A novel pipeline for the validation of manganese chelators for the treatment of manganese overload

Abstract Manganese neurotoxicity, arising from environmental overexposure or inherited transporter disorders due to pathogenic variants in SLC30A10 and SLC39A14, leads to manganism, a debilitating Parkinsonian movement disorder. Alhtough chelation therapy can partially reverse neuropathology, current clinical practice relies on intravenous CaNa2EDTA, which is burdensome and poorly suited for long-term use. Consequently, there remains a significant unmet need for more effective, orally bioavailable chelators. This study aimed to establish and validate a pipeline for identifying and assessing novel ligands that attenuate manganese neurotoxicity and support preclinical translational development. Based on the structural features of manganese-based MRI contrast agents, we selected two chelators, N-picolyl-N,N′,N′-trans-1,2-cyclohexylenediaminetriacetic acid (H3PyC3A) and ethylenediaminetetraacetic acid−benzothiazole aniline (H4EDTA-BTA), and their methyl ester derivatives, Me3PyC3A and Me4EDTA-BTA. These were evaluated in vivo using zebrafish (slc39a14U801/U801) and mouse (Slc30a10KO/KO) models of manganese overload. H3PyC3A and Me3PyC3A demonstrated greater manganese-mobilizing efficacy than CaNa2EDTA, improving locomotor behavior in slc39a14U801/U801 zebrafish. In Slc30a10KO/KO mice, intravenous administration confirmed selective in vivo chelation of excess manganese over physiological concentrations of zinc and copper. Although oral bioavailability was low (